I have made the HDTV plunge just two weeks ago. I wanted a nice large screen and after looking at a lot of options, I went for a Sony Bravia 46" LCD set. This is a 768 x 1366 resolution (not the 1080 line XBR set that costs quite a bit more). I find that the difference between plasma and LCD pictures is much less important then is used to. LCD has improved a lot in contrast and color accuracy. They also won't be affected by the burn-in problem which is still alive and well, and that you'll notice when switching from 4:3 to 16:9 modes. There are ways to minimize burn-in, but you cannot totally eliminate it...especially with a wife that never turns the TV off. I also find that the black space between pixels is much more noticable on plasmas then on LCDs, giving an annoying screen door effect if you're a bit close to it.
I liked the Sony for its multitude of inputs and discrete codes for power and input, an important automation advantage. It seems that Samsung and Sony both produce their LCD screens in the same factory, so picture quality should be similar for both brands. It also appears that Samsung has discrete codes, although I haven't verified this myself.
Anyway I'm happy with my new TV and the 768 line resolution doesn't both me at all, since I mostly use it to watch regular DVDs which are 480 line resolution. In fact I would think that the less amount of upscaling needed to go to 768 lines might be an advantage here in terms of image quality. To me, the 1080p thing sounds more like bragging rights then anything concrete. I saw an article a while back saying that it is only on screens 60" and up that it becomes noticable at all.