I just got this TV friday (and the DVI->HDMI cable saturday morning) and after a few hickups (turning off overscanning and removing+reentering the video card to remove odd on-screen artifacts) it's working out great in 1080p. The only problem I have with it is that it won't display the bios/boot up. After I boot, the signal will only be received around the time vista plays it's welcome sound. Previously had an LG LCDTV with 1360x768 hooked up which did display that bootup.
I had trouble with these saturday, but after testing again today (thank god i did) all of the previous as well as more (ALL those listed in Display Settings) now work great. Tested at 60Hz:
800x600 1024x768 1152x864
1280x720 1280x768 1280x800 1280x960 1280x1024
1360x768 1360x1024 1440x900 1776x1000
Using an ATi 1600 XT with a DVI->HDMI cable; same results whether i use the 'pc' side-HDMI or HDMI 1 (you never know)
Will be getting a GeForce 8800 GT sometime this week.
I'm running an Asus M2N-E if that matters...
Also, i have a 22" CRT stored in the attic i could use to fix/troubleshoot this, but i can't use it for a permanent solution (too big)