Since adding HA! to CodePlex, I have been averaging roughly 1000 hits and 20 downloads per week. That might not sound high to most of you, but for HA! it's a big leap. The original heroicadventure.com site probably averaged about 1/20th of that with the occasional bump now and then.
Currently I've got one other guy on the team and 1 contributor that will most likely end up on the team fairly soon.