As I was getting ready to upload this I discovered there are a fair number of pep8 failures with the added code.

 $ xvfb-run nosetests3
............................................................./home/bdmurray/source-trees/update-manager/trunk/tests/../tests/test_livepatch_socket.py:62:80: E501 line too long (127 > 79 characters)
/home/bdmurray/source-trees/update-manager/trunk/tests/../tests/test_livepatch_socket.py:83:80: E501 line too long (98 > 79 characters)
/home/bdmurray/source-trees/update-manager/trunk/tests/../tests/test_livepatch_socket.py:136:80: E501 line too long (94 > 79 characters)
/home/bdmurray/source-trees/update-manager/trunk/tests/../tests/test_livepatch_socket.py:137:80: E501 line too long (107 > 79 characters)
/home/bdmurray/source-trees/update-manager/trunk/tests/../tests/test_livepatch_socket.py:154:9: E306 expected 1 blank line before a nested definition, found 0
/home/bdmurray/source-trees/update-manager/trunk/tests/../tests/test_livepatch_socket.py:161:80: E501 line too long (80 > 79 characters)
F.F..................................
======================================================================
FAIL: test_pep8_clean (test_pep8.TestPep8Clean)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/bdmurray/source-trees/update-manager/trunk/tests/test_pep8.py", line 33, in test_pep8_clean
    self.assertEqual(0, ret_code)
AssertionError: 0 != 1

======================================================================
FAIL: test_pyflakes_clean (test_pyflakes.TestPyflakesClean)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/bdmurray/source-trees/update-manager/trunk/tests/test_pyflakes.py", line 56, in test_pyflakes_clean
    self.assertEqual(0, len(filtered_contents))
AssertionError: 0 != 8
-------------------- >> begin captured stdout << ---------------------
../tests/test_utils.py:5: 'glob' imported but unused
../tests/test_livepatch_socket.py:18: 'gi' imported but unused
../tests/test_livepatch_socket.py:186: undefined name 'logging'
../tests/test_livepatch_socket.py:186: undefined name 'logging'
../UpdateManager/Dialogs.py:29: 'gi.repository.GObject' imported but unused
../UpdateManager/Dialogs.py:30: 'gi.repository.Pango' imported but unused
../UpdateManager/Core/LivePatchSocket.py:23: 'gi' imported but unused
../UpdateManager/Core/LivePatchSocket.py:115: undefined name 'other'

--------------------- >> end captured stdout << ----------------------

----------------------------------------------------------------------

Sorry about asking for additional fixes, but could you address the ones in the code you've added?  Thanks!
/home/bdmurray/source-trees/update-manager/trunk/tests/../tests/test_livepatch_socket.py:162:60: E712 comparison to True should be 'if cond is True:' or 'if cond:'
/home/bdmurray/source-trees/update-manager/trunk/tests/../tests/test_livepatch_socket.py:170:9: E306 expected 1 blank line before a nested definition, found 0
/home/bdmurray/source-trees/update-manager/trunk/tests/../tests/test_livepatch_socket.py:175:80: E501 line too long (173 > 79 characters)
/home/bdmurray/source-trees/update-manager/trunk/tests/../tests/test_livepatch_socket.py:180:80: E501 line too long (80 > 79 characters)
/home/bdmurray/source-trees/update-manager/trunk/tests/../tests/test_livepatch_socket.py:181:60: E712 comparison to True should be 'if cond is True:' or 'if cond:'
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Dialogs.py:147:80: E501 line too long (81 > 79 characters)
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Dialogs.py:165:80: E501 line too long (90 > 79 characters)
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Dialogs.py:167:80: E501 line too long (113 > 79 characters)
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Dialogs.py:168:80: E501 line too long (84 > 79 characters)
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Dialogs.py:169:18: E111 indentation is not a multiple of four
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Dialogs.py:170:18: E111 indentation is not a multiple of four
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Dialogs.py:171:22: E111 indentation is not a multiple of four
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Dialogs.py:171:80: E501 line too long (89 > 79 characters)
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Dialogs.py:172:18: E111 indentation is not a multiple of four
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Dialogs.py:173:22: E111 indentation is not a multiple of four
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Dialogs.py:173:80: E501 line too long (112 > 79 characters)
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Core/LivePatchSocket.py:32:1: E302 expected 2 blank lines, found 1
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Core/LivePatchSocket.py:46:33: E251 unexpected spaces around keyword / parameter equals
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Core/LivePatchSocket.py:46:35: E251 unexpected spaces around keyword / parameter equals
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Core/LivePatchSocket.py:54:13: E731 do not assign a lambda expression, use a def
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Core/LivePatchSocket.py:68:80: E501 line too long (83 > 79 characters)
/home/bdmurray/source-trees/update-manager/trunk/tests/../UpdateManager/Core/LivePatchSocket.py:97:80: E501 line too long (101 > 79 characters)