i would be the same as using it on any smaller monitor, it is still considered the same resolution. the only issue with using a high resolution on a tv that big is it will be hard to see lettering on the screen if left at default, i use 720P for my desktop, and will sometimes switch sames to 1080 if the hud or words are not too small in game.
Should be no problems, just...
Check the TV will connect to your chosen graphics card. Most have HDMI connectors, but t's a wonderful world and you never know
If the TV is HDCP compliant, drop a Blu-ray drive into the system rather than a DVD, the extra cost is fairly small these days and it'll give you the godness of hi-def movies.
Remember to sit a reasonabe distance away.
Screen size is not what matters, but resolution, a 1920x1080 display takes the same amount of work from the computer to drive, whether it's 19 or 42 inches in size.