There has been no progress on this, so we can't for now merge this branch.  The comments we made above are still unresolved, and in particular, the full test suite reports errors in IPython.tests, and running

 iptest IPython.tests

produces this on my system:

uqbar[junk]> iptest IPython.tests
Could not open file <IPython.tests> for safe execution.
>f2("a b c")
>f1("a", "b", "c")
>f1(1,2,3)
>f2(4)
 os.path.isdir(path)
ERROR: File `refbug.py` not found.
ERROR: File `refbug.py` not found.
ERROR: File `tclass.py` not found.
ERROR: File `tclass.py` not found.
ERROR: File `tclass.py` not found.
======================================================================
ERROR: Check that %run doesn't damage __builtins__
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/fperez/usr/local/lib/python2.5/site-packages/nose-0.10.4-py2.5.egg/nose/case.py", line 182, in runTest
    self.test(*self.arg)
  File "/home/fperez/usr/lib/python2.5/site-packages/IPython/testing/decorators.py", line 171, in skipper_func
    return f(*args, **kwargs)
  File "/home/fperez/usr/lib/python2.5/site-packages/IPython/tests/test_magic.py", line 261, in test_builtins_id
    bid1 = id(_ip.user_ns['__builtins__'])
KeyError: '__builtins__'

======================================================================
FAIL: Test that prompts correctly generate after %run
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/fperez/usr/local/lib/python2.5/site-packages/nose-0.10.4-py2.5.egg/nose/case.py", line 182, in runTest
    self.test(*self.arg)
  File "/home/fperez/usr/lib/python2.5/site-packages/IPython/testing/decorators.py", line 171, in skipper_func
    return f(*args, **kwargs)
  File "/home/fperez/usr/lib/python2.5/site-packages/IPython/tests/test_magic.py", line 284, in test_prompts
    nt.assert_equals(p2[:3], '...')
AssertionError: '\x01\x1b[' != '...'
>>  raise self.failureException, \
          (None or '%r != %r' % ('\x01\x1b[', '...'))
    

======================================================================
FAIL: Doctest: IPython.tests.test_magic.doctest_hist_f
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/fperez/usr/lib/python2.5/site-packages/IPython/testing/plugin/ipdoctest.py", line 430, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for IPython.tests.test_magic.doctest_hist_f
  File "/home/fperez/usr/lib/python2.5/site-packages/IPython/tests/test_magic.py", line 71, in doctest_hist_f

----------------------------------------------------------------------
File "/home/fperez/usr/lib/python2.5/site-packages/IPython/tests/test_magic.py", line 78, in IPython.tests.test_magic.doctest_hist_f
Failed example:
    _ip.magic("hist -n -f $tfile 3")
Exception raised:
    Traceback (most recent call last):
      File "/usr/lib/python2.5/doctest.py", line 1228, in __run
        compileflags, 1) in test.globs
      File "<doctest IPython.tests.test_magic.doctest_hist_f[2]>", line 1, in <module>
        _ip.magic("hist -n -f $tfile 3")
      File "/home/fperez/usr/lib/python2.5/site-packages/IPython/iplib.py", line 1180, in ipmagic
        raise UsageError("Magic function `%s` not found." % magic_name)
    UsageError: Magic function `hist` not found.

>>  raise self.failureException(self.format_failure(<StringIO.StringIO instance at 0x39a1200>.getvalue()))
    

======================================================================
FAIL: Doctest: IPython.tests.test_magic.doctest_hist_r
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/fperez/usr/lib/python2.5/site-packages/IPython/testing/plugin/ipdoctest.py", line 430, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for IPython.tests.test_magic.doctest_hist_r
  File "/home/fperez/usr/lib/python2.5/site-packages/IPython/tests/test_magic.py", line 83, in doctest_hist_r

----------------------------------------------------------------------
File "/home/fperez/usr/lib/python2.5/site-packages/IPython/tests/test_magic.py", line 88, in IPython.tests.test_magic.doctest_hist_r
Failed example:
    'hist' in _ip.IP.lsmagic()
Expected:
    True
Got:
    False
----------------------------------------------------------------------
File "/home/fperez/usr/lib/python2.5/site-packages/IPython/tests/test_magic.py", line 93, in IPython.tests.test_magic.doctest_hist_r
Failed example:
    _ip.magic("hist -n -r 2")
Exception raised:
    Traceback (most recent call last):
      File "/usr/lib/python2.5/doctest.py", line 1228, in __run
        compileflags, 1) in test.globs
      File "<doctest IPython.tests.test_magic.doctest_hist_r[2]>", line 1, in <module>
        _ip.magic("hist -n -r 2")
      File "/home/fperez/usr/lib/python2.5/site-packages/IPython/iplib.py", line 1180, in ipmagic
        raise UsageError("Magic function `%s` not found." % magic_name)
    UsageError: Magic function `hist` not found.

>>  raise self.failureException(self.format_failure(<StringIO.StringIO instance at 0x3d65170>.getvalue()))
    

======================================================================
FAIL: Doctest: IPython.tests.test_magic.doctest_refbug
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/fperez/usr/lib/python2.5/site-packages/IPython/testing/plugin/ipdoctest.py", line 430, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for IPython.tests.test_magic.doctest_refbug
  File "/home/fperez/usr/lib/python2.5/site-packages/IPython/tests/test_magic.py", line 156, in doctest_refbug

----------------------------------------------------------------------
File "/home/fperez/usr/lib/python2.5/site-packages/IPython/tests/test_magic.py", line 164, in IPython.tests.test_magic.doctest_refbug
Failed example:
    call_f()
Exception raised:
    Traceback (most recent call last):
      File "/usr/lib/python2.5/doctest.py", line 1228, in __run
        compileflags, 1) in test.globs
      File "<doctest IPython.tests.test_magic.doctest_refbug[2]>", line 1, in <module>
        call_f()
    NameError: name 'call_f' is not defined
----------------------------------------------------------------------
File "/home/fperez/usr/lib/python2.5/site-packages/IPython/tests/test_magic.py", line 169, in IPython.tests.test_magic.doctest_refbug
Failed example:
    call_f()
Exception raised:
    Traceback (most recent call last):
      File "/usr/lib/python2.5/doctest.py", line 1228, in __run
        compileflags, 1) in test.globs
      File "<doctest IPython.tests.test_magic.doctest_refbug[4]>", line 1, in <module>
        call_f()
    NameError: name 'call_f' is not defined

>>  raise self.failureException(self.format_failure(<StringIO.StringIO instance at 0x383b6c8>.getvalue()))
    

======================================================================
FAIL: Doctest: IPython.tests.test_magic.doctest_run_ns
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/fperez/usr/lib/python2.5/site-packages/IPython/testing/plugin/ipdoctest.py", line 430, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for IPython.tests.test_magic.doctest_run_ns
  File "/home/fperez/usr/lib/python2.5/site-packages/IPython/tests/test_magic.py", line 181, in doctest_run_ns

----------------------------------------------------------------------
File "/home/fperez/usr/lib/python2.5/site-packages/IPython/tests/test_magic.py", line 186, in IPython.tests.test_magic.doctest_run_ns
Failed example:
    isinstance(f(),foo)
Exception raised:
    Traceback (most recent call last):
      File "/usr/lib/python2.5/doctest.py", line 1228, in __run
        compileflags, 1) in test.globs
      File "<doctest IPython.tests.test_magic.doctest_run_ns[1]>", line 1, in <module>
        isinstance(f(),foo)
    NameError: name 'f' is not defined

>>  raise self.failureException(self.format_failure(<StringIO.StringIO instance at 0x3d70908>.getvalue()))
    

======================================================================
FAIL: Doctest: IPython.tests.test_magic.doctest_run_ns2
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/fperez/usr/lib/python2.5/site-packages/IPython/testing/plugin/ipdoctest.py", line 430, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for IPython.tests.test_magic.doctest_run_ns2
  File "/home/fperez/usr/lib/python2.5/site-packages/IPython/tests/test_magic.py", line 191, in doctest_run_ns2

----------------------------------------------------------------------
File "/home/fperez/usr/lib/python2.5/site-packages/IPython/tests/test_magic.py", line 196, in IPython.tests.test_magic.doctest_run_ns2
Failed example:
    _ip.magic("run tclass C-second_pass")
Expected:
    tclass.py: deleting object: C-first_pass
Got nothing

>>  raise self.failureException(self.format_failure(<StringIO.StringIO instance at 0x3d70cf8>.getvalue()))
    

----------------------------------------------------------------------
Ran 59 tests in 0.513s

FAILED (SKIP=11, errors=1, failures=6)
obj_del.py: object A deleted


######################################

On trunk this all works fine, so this branch looks like it still needs a fair amount of work (or at least a careful bit of it to find where these errors are coming from).