Tried out Mythbuntu 7.10 (release) last night on a test machine and it appears to mostly work. I like the new theme... good job!
However I noticed that of the few video files placed into '/var/lib/mythtv/videos' none are listed in the Video Manager, so I am unable to enter information about them into the database.
At first they would not play either, but installing the codecs appears to have fixed that. Even then they are not listed.....
One thing to note is that this test machine does not have a capture card, and is used for pre-recorded material only. So that might be an issue.