On a personal note, one thing I would like to see on BuddyPress is a complete Groups hierarchy with (multiple) parents, siblings and child groups. I reckon this would open a whole new market for things like geneology (big business).
Also I think you should take a good look at the rival product BuddyBoss, which, feature wise, is ahead of Buddypress in so many ways. A good media integration for example is a must have, likewise a file download system. BP could have the edge on its rival though, simply because the latter concentrates on Premium features.
Just my 2 cents
