The things I would like are
Tooltips, ease of use things, clear labels : I had to watch the video to figure out how to do things. Messaging to communicate how to do things would be very helpful.
True IK that adjusts all bones necessary, not just one bone back
On that note, the ability to set acceptable angles for bones to bend, so shoulders automatically don't pop out of sockets
Skew/stretch, just a really important animation thing. Check out #1 on this list for details. http://art-eater.com/2010/07/test-1-darkstalkers/
Good product so far, needs a bit more to be great though!