For those of you not subscribed to bitcoin-development@lists.sourceforge.net :
We've been having a productive discussion of a proposal for a simple payment protocol to get a much better user experience than is given by bitcoin addresses:
http://sourceforge.net/mailarchive/message.php?msg_id=30147926
This is the next big "lets all agree to do things the same way" thing I think we should tackle. Latest pseudo-spec is: https://gist.github.com/4120476
I'd prefer to keep the discussion on the mailing list (I think this forum is a great place for brainstorming, but I think the mailing list is a little better for getting consensus on all the nitty-gritty details of a proposal).