Resolution is over-rated and misunderstood by most consumers. The "need" for 1080p is dependent on the combination of screen size and viewing distance. While you may be able to see a slight difference between a 1080p set and a 720p set when doing head to head comparisons, is that slight difference worth the price? Another question is whether you are okay with knowing that you don't have the latest/greatest?
For me, if you can control the light very well in a room then plasma would be my only option. Some plasmas (particularly the Panasonics) have an anti-glare screen. Still not as good as a LCD's, but better than having a standard screen. Even though LCDs are getting better in PQ, I still think plasmas have better detail (especially with blacks) and their higher refresh rate is a no brainer for the sports fan.
EDIT: (just seen T7's post). I have to agree about 1080p vs 720p. I have a 720p 50" plasma. Mine was about 1600 when I bought it. Now you can get one for about half that. If I had to buy a TV today, I would get the exact thing I have now and save my money.
im thinking about moving the 46 in bravia into the living room and getting a 50 inch plasma in the sports/movie room. Just dont want to be dissapointed in the plasma compared to the sony since a 50 inch would be to big for the living room. Plus it has a lot of light