What would you do with HD video on a 480x320 screen?

Anyway, it'd need an extra chip to work, which would make the phone bigger, and then it'd kill your battery when you used it (receiving signal, decoding video, playing sound and keeping the screen lit), so it would be useless in all but a few scenarios, like riding the bus to work (but is there anything worthwhile on at that time...).

I used to have a TV-tuner for my Game Gear. Used it maybe three times. It's a useless gimmick 95% of the time.

Other than live sporting events, can you think of anything that broadcast TV would provide that can't be served by the download/sync model? Given the additional chipsets and battery drain from heavy network use I can't see how Apple would view this particular desire as anything more than a need to break the populace from this idea that you watch video programs when some TV network thinks that you should watch them. If the content producers offered Apple access to their content at the same per-subscriber price point that they offer the content to the cable networks then your desires would be met in a much more interesting and appealing fashion.

Flash support?

Actually, I hear Slingbox has a pretty decent app for it (WiFi only though).