Comment 1 for bug 459891

Howdy, and thank you for helping to improve Mythbuntu by opening this ticket. I've reproduced that Mythbuntu is listed twice (this on a 9.04 upgrade to 9.10, compared to fresh install of reporter). This is due to the symbolic link put in for the Mythbuntu theme rename:
lrwxrwxrwx 1 root root 34 2009-10-24 21:16 /usr/share/mythtv/themes/Mythbuntu-9.10 -> /usr/share/mythtv/themes/Mythbuntu

Removing /usr/share/mythtv/themes/Mythbuntu-9.10 resolves this issue. The best thing to do would be to select a different theme altogether, then remove the link, then go back and select whichever of the Mythbuntu's is remaining.
While reproducing the above issue, I noticed there are also two different menu themes with the same name (default and Default).
As for blootube missing, it and a few other themes were removed because they were not completely ported to the new user interface.