BitTorrent Inc. acquired uTorrent in 2006 and promised a Mac client "soon." It took a while, but a build of the long-awaited uTorrent Mac is available. On BitTorrent.
It's not an official release, most likely an alpha but it feels pretty solid at first blush. If you feel like playing, uTorrent 0.1 was posted on Pirate Bay a few hours ago (seed people, seed). The (alpha?) build carries creation and modification dates of 15 September 2008, a week ago.