I have written in the past that I have a number of problems with Vista. However, I bought a laptop for which I had no choice but to accept Vista installed. I have not really been pleased with the interface -- as is Microsoft's wont, every option you really use is in a new place in this version. Hopefully I will get used to it, but I never, for example, was able to get used to the XP-style control panel, so I am not sure.
One thing Vista does NOT do very well is legacy games, particularly on a laptop where having up-to-date graphics drivers depends on the computer, rather than the chip, manufacturer (I am not sure why, but you can almost never use the generic Nvidia drivers for Nvidia cards on a laptop). Many copy protection schemes in older games will not recognize the CD in the tray in Vista, and a lot of legacy hardware components will never have Vista drivers written for them.
So I embarked on trying to dual-boot Vista with XP on a system that already had Vista installed on the whole hard disk out of the factory. It turned out to be tedious, but following these directions got me there perfectly (these directions cover going from XP to Vista+XP). I used Gparted to change the partitions around, which was much easier than I thought it would be, and EasyBCD is an awesome product (both are freeware). The only problem I had was the same as the one in comment #52 of the article, but the link and workaround linked there solved the problem for me.
I don't think I would have a total noob try this, but it also isn't some complicated haxor procedure either. Highly recommended for those of you with legacy software and equipment who want to try Vista or are stuck with it on your new computer.