First up, we have Ivan Komarov working on improving ICQ. I don't really use ICQ, so I can't say much, but if you do, hopefully there'll be a lot of great things coming out of it that will be useful to you. Next up is Adam Fowler working on a better chat log viewer. People really seem to complain about what we have now and at the very least, it's kind of slow once you have a lot of logs, so there should be room for some good improvements there. And then we have Gilles Bedel working on detachable libpurple sessions. I'm not sure how often I'd use it, but every once in a while, I feel like checking in on Pidgin from the laptop and it's a very painful process through SSH and D-Bus. This project should make that sort of thing much simpler. Finally, we have Jorge Villaseñor Salinas working on refactoring MSN.
So that last one is the one I'm mentoring. Personally, I've been wanting to re-write bits and pieces of the MSN prpl for a while now, but I've never had the time to get around to it. Jorge's already done some great work getting custom smiley support working for Pidgin 2.5.0. I'm sure he'll have no problem re-working the MSN prpl. I'm looking forward to getting a more structured and (hopefully) well-designed prpl which should make development a lot easier and quicker.