Apple has just seeded the 3rd beta of iTunes 10.5.1 to developers with performance enhancements and some stability improvements. The latest beta, which is now available on the iOS Developer Center, allows for further testing of the new iTunes Match. Apple supposedly wiped all existing iTunes Match libraries stored in iCloud earlier today to “prepare for the launch of iTunes Match“.
Here are the Beta 3 Release Notes:
iTunes 10.5.1 beta 3 includes a number of important stability and performance improvements for iTunes Match, and is a required update for all subscribers to iTunes Match beta.
Backup regularly and do not delete the music you add to iCloud from your computer. Apple may periodically delete all iCloud libraries during the beta period.This will require you to scan, match, and upload songs again