I talk to myself.
Edit: I could provide the logic in it though. Apple has pared down the ATV to one model which likely means either a discontinuation of the line or a significant upgrade is in the works (I feel discontinuation is unlikely). The current ATV and AV dock ship with the old remote, which indicates that they are both in need of an upgrade. Tests have shown the iPhone 3GS to be capable of playing back some 1080p video, and the Zune HD has a 720p dock, so I would guess that the AV dock will be upgraded to match alongside an OS update allowing the iPhone 3GS and iPod touch to play back 720p video of course (a nice mid cycle purchasing incentive). Clearly Apple wouldn't want the AV dock to be as capable as ATV, so ATV naturally goes to 1080p (which of course requires an update to the iTunes store as well).
Now if changes of this magnitude were to happen, a video centric event would be a must. Apple says the holiday lineup is set. AI suggests a tablet announcement in January, so a January video event it is (I say late January because I don't think they will get it all together before then). If Apple does become serious about Apple TV, it will require yearly revisions and a new ATV and Tablet every year would be more than enough for an annual video event.