What does that mean for Quicksilver's users? Probably not a lot, although with a few interested developers on board, it'll probably mean quicker updates and more responsive bugfixes. Even Alcor says in the thread that while bugfixes and updates are planned for Leopard, he has no idea when they'll actually be released, and an open source app would probably make specific fixes faster.
As for a timeline on making it open source, Alcor doesn't promise anything too exciting on that end, either. He does say that the OS version of Quicksilver will be for Leopard, so we're looking at least at October, if not later. But if Quicksilver is going open source, it likely means that one of the Mac's best applications will only get better.
[ via DJ ]