A little more than an hour after the public release of iTunes 10.5, the beta of iTunes 10.5.1 with iTunes Match was pushed to developers.
As commenters have noted, iTunes 10.5 disabled iTunes Match, so for developers who are testing the service, you'll want to head to the Apple Developer Center and grab the beta of iTunes 10.5.1. iTunes will most likely be updated to 10.5.1 when iCloud is formally released to the public on Wednesday.
