If you are into football, then DEFINTELY get the HD set.
You will need just the HDTV compatable TV set, and you will need a new DirecTV receiver the prices of the tv varies, and the rcvrs are anywhere between about $350-500.
That being said, here is some insider infor for you:
-This season, CBS will be airing their 'A' college game every week in HDTV. Depending on Sponsorships, they will also be producing a number of regular season games in HDTV and all post season action is done in HDTV (all of these games you can pick up in full 1080i (the 'better' standard for HDTV) on DSS)
All analog stations are supposed to be taken off the air in 2007, and replaced with HDTV broadcasts only. Now would you really want to spend all this money now on a BIG tv and in 5 years have to watch everything on TV in letterbox format?
Spring for the extra bucks now and pick up an HD set. I personally like what I have seen from Sony, Mitsubishi, and Panasonic as far as nice looking sets.
If you got any more ?'s shoot me a PM.
bern