I've had a couple of clients that had membership/forum sites and asked me about allowing their users/members to edit their avatars without Gravatar getting involved. An understandable and reasonable request, you'd think. After trying to code around it, and realizing how much time and money was going into such a simple project for them, I had to advise them they're stuck with Gravatar as long as Matt is running WordPress. Piling on plugins for non-essential functions like this starts to add up and usually isn't a perfect solution anyway. I would love to see the cord cut between Gravatar and WordPress.