Developers, be aware that Apple is planning to reset all iTunes Match data on September 26th at 9AM PDT—like they did with iCloud earlier this week. This reset suggests an imminent release of an iOS 5 Gold Master build, which should be followed shortly by a public release. The iPhone 5 is expected to be announced on October 5th, which jives with this announcement.
Apple mentions that devs should disable Match to prepare for the reset, and notes that music stored locally should not be effected. As always, make sure to have a backup handy just in case.