At that price range, you can get the entry level D-SLR with HD video, or if you want something smaller then you can look into the micro 4/3 from Panasonic (GF1) or Olympus (E-PL1) or Sony's NEX 3 or 5.

I only shoot 1080 HD video, they look great on 50 in plus HDTV. The 720 resolution is more for computer monitor screen and internet HD video use, will not be as good as the 1080 on your 50 in HDTV (unless you have the older generation of HDTV). The older generation of HDTV, a decade ago (when there is still EDTV and use DVI instead of HDMI), may have 720 resolution rather than 1080. Some people may still have these sets because they cost more than the 3D HDTV today.