Nothing to worry about. Just get your new monitor plugged in with the DVI cable and let your PC start itself up. Windows will automatically adapt itself to the new monitor. 1600x1200 (2D) is piece o' cake for a 6800NU.
After that, search for backlight bleeding and dead pixels. If you can't find anything, just do your usual thing at your computer. Play some games as well. At the end of your computer session (i.e., before you shut down your PC), check your LCD again for backlight bleeding and dead pixels. If there are none, you're
almost guaranteed to have a rocksolid LCD without dead pixels.
I'd still pay some attention to it in the next few days. Let's say, if nothing occurs after one week, you have got a fantastic LCD monitor. If something does occur, you'll have to return it and get a new one under the RMA policies, depending on the severity of the problems. This is because I've read that some people suddenly got dead pixels after a couple of days. It's sucky, I know, but it can happen.