According to BGR, an inside source has tipped them off about a possible 7" Apple Tablet being announced in January. The source was not sure if they will be releasing a 10" tablet alongside the 7", but is 100% sure that they will announce the 7" tablet next month.
BGR confirmed that this inside source has provided information to them in the past, and was accurate with the leaked information.
Apple also alerted a select group of developers to get ready for next big wave of applications, asking developers to add full screen support to their applications. Currently developers only support the iPhone and iPod touch at a fixed 320x480 resolution.
The Apple Tablet will support the same operating system as the iPhone and iPod touch and should have similar hardware such as multi-touch technology, accelerometer and WiFi. No official specifications have been released as of yet, but we will likely hear the full specifications in January.
The rumors indicate that Apple will demonstrate the tablet next month, but will not release the product commercially just yet. Apple wants to give developers time to add tablet support. The tablet computer is believed to just be an iPod touch, scaled up to about four times the size.