Apple has announced that it will reset developers iTunes Match iCloud Libraries on Monday September 26.
This is a similar to lasts week's announcement, where we saw Apple resetting developer’s iOS 5 iCloud backups.
To continue to improve the overall quality and reliability of iTunes Match, it has become necessary to delete all current iCloud libraries.
All iCloud libraries will be deleted on Monday, September 26th at 9AM PDT. To prepare, please turn off iTunes Match on all of your computers and iOS devices. On your computer, choose Store > Turn off iTunes Match. On your iOS device, tap Settings > Music, then turn off iTunes Match. The songs on your computer should not be affected. As always, please backup regularly and do not delete the music you add to iCloud from your computer.
Apple is probably resetting iCloud data in preparation for an early October launch of iOS 5. We should hopefully find out on October, which is the rumored date for the next iPhone launch event. However Apple has still not confirmed this date or even an event as of yet. Hopefully that will happen next week.