Take the advice of Conjur and read up first. Widescreen and HDTV is a bit different than a SDTV 4:3 set. If you watch Sat TV, you are going to be upset with the quality, because you will now see the compression. However, the HDTV broadcasts look amazing. So do Gamecube or Xbox using progressive scan (Xbox may have real HDTV games in future, above 480p resolution). And not to forget DVD, which will be amazing (get a progressive scan DVD player).
As a note, you can possibly do better at Sears if you find the right salesperson, they will pricematch web sites. (I ended up with something Sears normally sells for $4999, getting it for $2250 + tax, free delivery).
PPS: If you have stairs to go up, seriously consider one that comes apart!!! The Mitsu 65" splits in to two pieces, so you can make it around almost any bend.