Thanks for the feedback! That's an interesting idea. Right now, registered users can click "I'm working on it" on a given bounty to privately signal to the bounty creator that they have started work. I was hesitant to make the list of current workers public because it might dissuade other would-be solution providers from answering, since they might assume that the other user is almost done with the problem (when they might not have done anything at all). I might add in some kind of "I'm working on it" track record for each user, so people can see how often they actually solved problems they said they'd be working on. Thanks for bringing that up.