ThinkSecret provides confirmation for an earlier Page 2 Rumor.
According to the report, Apple will be quietly updating the Mac mini in the next week. The low end Mac mini will be upgraded from 1.25GHz to 1.33GHz and the high end from 1.42GHz to 1.5GHz. Internal components such as AirPort Extreme and Bluetooth will receive upgrades as will the SuperDrive (up to 8x) in the high end Mac mini model.
Prices are expected to remain the same.
The Mac mini just received minor upgrades in July. Such a gradual upgrade process is consistent with a long standing goal of Apple wanting to de-emphasize Expo events for product releases.