Unless there's a specific set of programs that aren't Vista compatible I'd get one with Vista preinstalled. That would save you the cost of purchasing the upgrade down the road, another $100+, and also ensure the system is truly designed for Vista...if it doesn't work you can take it back. Remember, a computer can be labeled as Vista ready but still have major driver issues, which is why a lot of people have reported problems after upgrading. Start with Vista to avoid such hassles.
Another option is to just purchase a copy of Vista and install it on your current computer, assuming you're not looking specifically for a more powerful system. Regardless, you can click here to download a 30-day trial copy of Vista. It only runs in a virtual machine (you'll need the free VirtualPC software from Microsoft of VMWare's free VM Player), but it's a nice way to 'get your feet wet' before making the final plunge. Just be aware of the additional RAM requirements before running it.
Hope this helps,
i have an amd 64 single core now with XP home. a trusty workhorse. so i am not under any pressure to make a rapid shift to vista.
if it were you, at this point in time, would you buy a computer which already has vista loaded, or one that has XP media center with the thought of later upgrading to vista as it improves?
my thinking is that the two machines i have in mind are essentially the same cpu and hard drive wise. i wanted to start tinkering and familiarizing myself with vista as it appears to be the next thing. i can still use my single core machine as i acquaint with the new operating system. good idea?
thanks in advance.