Following Apple’s clearing of developer iTunes Match libraries on Saturday, the company has now seeded developers with iTunes 10.5.1 Beta 3. The update includes numerous stability and performance improvements for iTunes Match.
The Beta 3 Release Notes contain a warning that Apple might again wipe the iTunes match data during their 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.
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
Apple’s iTunes Match service is a $25 per year service that matches your existing iTunes library with high-quality 256Kbps versions in Apple’s iCloud. Apple had announced release of the service for late October, but it has pushed it back with no clear launch date announced. Recent reports suggest a launch date is quickly approaching.