Actually, I do have a 50" plasma HDTV connected to my PC that does 720p. I've played STO on it before a few times but honestly, it looks a lot better on my 22" LCD. I haven't tried playing it on an LCD HDTV or one that does 1080 so I couldn't say how good it looks as far as that goes.
I have my PC duelled on a 24 inch monitor and a 42 inch LCD.
I do run STO on the 42 inch most of the time, but unfortunately the 42 can only run a max of 1360x 768 without the picture becoming ether disproportionate or out of range. Where as my 24 runs 1440x900.
Which means STO looks better on my smaller screen, which is disappointing.