The whole 1080p is so ridiculous that I wish television wasn't even invented so that this issue would have never come up. 1080p is nothing more than a super lame marketing trick that companies are trying to pull on the hi-def early adopter crowd so that the super-geeky will rebuy even more expensive tvs, and the not-so-geeky will spend more than they have to. At any reasonable viewing distance and screen size the change in resolution isn't going ot make a lick of difference in any way whatsoever. Even at the larger viewing sizes you'll be hardpressed to see a difference.
And that's IF you can actually find something that sends out 1080p. Right now the only sources of 1080p content are Blu-Ray players and HD-DVD players, except the 1080p version of the HD-DVD player isn't even OUT yet (the discs are 1080p though). Other than that, you're only going to find 1080p in professional A/V situations where you're looking at the tens of thousands of dollars.
720p and 1080i are more than perfect for everything you're going to watch. And the hilarious thing is that there's actually no difference between 1080i and 1080p for video content. With 1080i you're getting a 1920x1080 image ever 1/30 of a second, same goes for 1080p. The only difference would come at 1080p at 60FPS, which will only happen with the next-next generation of videogames (6 years down the line).
The real question is, should you go for a native resolution of 1080i or 720p? And in that regards, it STILL doesn't matter! Both resolutions are fantastic and give an ultra-clear and crisp picture. Some tv stations broadcast in 1080i, and others in 720p, so no matter what you go with, there's going to be some scaling going on. That's why one of the most important aspects to the tv is the scaler, since it WILL be used.
Now let's never talk about 1080p again.