Consider that Apple has now embraced 1080p with the launch of the iPhone 4s. Every video shot with that is a 1080p video looking for an outlet to our 1080p HDTVs. The existing

TV can receive that video but is hardware capped on the output at 720p. This alone is a sign that 1080p is likely coming soon.
Consider that a new iPad3 is coming soon. Principal among its rumored benefits is the so-called "retina" display. Most people seem to believe it is going to follow the iPhone "retina" upgrade by simply doubling both the horizontal & vertical resolution of the existing iPad. If so, it's screen resolution will be 2048 X 1536. 1080p resolution is 1920 x 1080. The upscale of HD video from 1920 to 2048 should look very nice on that new screen. The upscale of (existing 720p) 1280 to 2048 will not look as nice. This may point to a new tier of HD video in the iTunes store at 1080p, joining the existing options of 720p and SD. If so, that will beg for a new

TV3 to also leverage that tier of video.
Consider that this iPad3 would be pretty favorable to get that 1080p video camera as well. Other than holding something back for the iPad4, why shoot only 720p to then try to scale it up to 2048 x 1536? If it goes 1080p, that's another mainstream device begging for someone to push those home videos to our 1080p HDTVs. Once again, this would beg for an update to the

TV.
There should be a point where Apple will want to put the new iDevice CPU inside the

TV box rather than continuing to make the old CPU. The newer CPU is plenty capable of pushing 1080p to an HDTV. It becomes a "might as well" proposition for such an upgrade.
Apple gave us iMovie HD in- what- 2005 or 06? It's been able to import, edit and export 1080HD video ever since. iTunes can import 1080p and it plays via iTunes just fine. All the (Apple) pieces are in place except this ONE piece.
Just about everything in consumer HD now touts "Full HD" as 1080p. Apple is marketing one of the few things that still pitches the "HD" tag but only pushes 720p (and a limited version of it at that). Cheap competitor set-top boxes are all 1080p and have been for some time. And- even HERE- it is obvious from many threads about 1080p that there appears to be a good-sized pocket of ready buyers for a 1080p

TV3. Apple likes to sell hardware; maybe finally give all buyers what they want?
Obviously, I expect an

TV3 sooner than later.