The long rumored Apple TV 3 may finally be unveiled by Apple on March 7 as part of the just confirmed iPad 3 event. According to 9to5Mac's Mark Gurman, the device is code named J33, will have "near immediate" availability, and a "mystery accessory" will be available along with it:

We’re not sure what it is, but it’s called “B82″ internally. The product is likely some accessory, probably ranging from either a cable, cover, or new audio remote. The new Apple TV will include Bluetooth 4.0 capability, so perhaps Apple will ship an improved remote to that takes advantage of that next-generation Bluetooth protocol.

Rumored features of Apple TV 3 include 1080p video playback with potential 1080p iTunes content to go along with it, as well as Bluetooth 4.0 and an upgraded processor, either the suspected dual-core Apple A5X or quad-core Apple A6.

Combined with AirPlay on iOS, and the upcoming AirPlay on OS X Mountain Lion, it could finally take Apple TV from "hobby" to necessity. I for one will never be transcoding a video or storing anything in an iTunes library again.

Source: 9to5Mac