Right now if you purchase a laptop with XP pre-installed you are eligible to receive a free or very low-priced upgrade to Vista, giving you the option down the road. However, if you purchase a laptop with Vista pre-installed you do not receive a copy of XP. Thus, while it's easy to remove Vista and install another OS you would have to pay for a copy of XP out of your own pocket. Personally, if you're leery of Vista, I would either buy an XP system now while they're still available in stores or purchase an XP laptop off Ebay or the like later. Then again, if you're not worried about paying a $100+ extra then it doesn't matter which way you go.
I was planning to get a new laptop in the summer, but I've heard that within a month or two it will be all but impossible to buy a new laptop with XP pre-installed, as all will have Vista instead. I don't want Vista. Is it possible / problematic to wipe Vista off the machine and install a (new, legit) version of XP?