I might think about going from XP to Vista at some point, but would all XP programmes, including games, work? (I've heard about Norton AV having some troubles, but wouldn't touch it with a barge-pole in any case.)
Also, would the 64-bit version actually speed anything up on my 64-bit processor, or would that only happen when new applications are written as native 64-bit?
As far as I am led to believe any program that will run on the 32 bit version Vista will run on the 64 bit version albeit at 32 bit speeds. The only advantage in terms of speed and performance would be if you used a 64 bit program, then this would be faster, but theres not a lot of 64 bit programs about yet so for most people its a waste of time. Plus I'm sure you have read about the lack of drivers for 32 bit Vista and its worse for the 64 bit version of Vista and as Kate B has said the drivers must be WHQL certified. In the case of the 64 bit version if they are not then windows will not allow them to install.
If I am wrong in any way I'm sure someone will correct me but this is my understanding and because of this lack of programs, lack of drivers and the subsequent problems at this time I think its asking for trouble. If there are a lot more programs written for 64 bit in the next year and proper drivers are made available then it might be worthwhile then - notice I said might.
Sounds like buying 64-bit AMD processors (& more recently Intel ones) that were hyped by PC sellers was a waste of time. By the time a suitable reliable OS is available many of the processors will be old hat anyway. Only thing worth a try might be a Linux OS, I suppose, but I doubt there are any applications that make it worth buying a decent Linux distribution such as SuSe.
My son uses Dragon Naturally Speaking to dictate his GCSE coursework & I was hoping 64-bit computing would make things like that zoom along, not to mention improved games. In fact neither the latest version of DNS or games programmes are 64-bit yet. (Don't know whether the dictation software that comes with Vista can work in native 64-bit mode. MS software doesn't ussually compare with what specialist companies produce anyway...)
CodenameCueball: Lots of RAM sounds nice for dictation programmes, etc., but who can afford to buy 4 x 1MB, never mind 4 x 4MB, assuming such sticks exist? I reckon plenty of people have a setup something like mine (2 x 256 + 2 x 512 MB), which means you have to chuck everything away & start from scratch to make a big RAM upgrade possible.