It depends. I've been using XP x64 on my desktop for a few months now, and I have drivers for all my hardware and peripherals. Most of your existing 32-bit software should also work just fine, unless it installs some kind of driver or shell extension. Many software vendors have also started coming out with native 64-bit applications as well. The only app I currently miss on my x64 box is Windows Desktop Search, but other than that, everything runs great.
You can also take a look at the x64 wiki that I set up. It's a work-in-progress, but it lists compatible and incompatible software and hardware. Some of our other members have also been contributing to it, so if you decide to go with x64, you might be able to help us out by letting us know of anything that's missing in the list. http://netryder.osnn.net/x64
see i always thought that since the os was 64 it would not be faster, boy was i wrong when i did some research, when i get my laptop back im probably ganna install x64 because the bastards fromatted my hard drive with me strictly telling them not to. anyways i think stability is also one of the positives?
well since the os is 64 bit, it is faster. its difficult to tell for me since when i upgraded I upgraded my PC substantially, so difficult to compare direct speeds. 64 bit apps should see a performance increase under heavy load. Stability is very god but then again I never had a problem with XP
Khayman's right. Honestly, if you have major stability issues with XP, don't expect any miracles from XP x64. The instability is almost certainly coming from poorly written third-party software, crap hardware, or shoddy drivers. Every OS has its bugs and issues, but you should NOT be experiencing major hangs, crashes and freezes under normal circumstances with XP, whether it be the 32-bit version of x64.