Media event set for September 9, launch likely ~10 days later.
Apple Releases iTunes 10.5.1 Beta 3 for More iTunes Match Testing
After again wiping iTunes Match libraries today, Apple has seeded developers with the 3rd iTunes 10.5.1 Beta. This update includes a number of important stability and performance improvements for iTunes Match.
Apple wiped iTunes Match libraries stored in iCloud earlier today in order to "prepare for the launch of iTunes Match". The Beta 3 Release Notes warn that Apple may again wipe iTunes match data during their ongoing testing:
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.iTunes Match is Apple's $25/year subscription service that will match your existing iTunes library with 256-Kbps versions in the iCloud. iTunes Match had been scheduled for release in late October, but has been pushed back without any clear launch date available. Apple's wording in the most recent emails suggests an imminent launch.
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