The thing is, I have an E6600 and an 8800GTX and 2gig of good RAM etc. So my hardware should be plenty good enough to deal with the improved OS. But no matter what the hardware is, it seems games will run slower no matter what. It may only be 10fps, but still, that seems like an issue to me. The games I can run at 90+ fps are not a problem. But there are some games that struggle to run already.. So moving to Vista could make them unplayable unless I lowered the graphics settings even further. And doing that on this kind of hardware would be kind of heart breaking.
I also think that, bearing in mind how much money I've spent on Creative's stupid hardware over the years, if I moved to Vista and than had problems with the drivers... I would be tempted to hunt down and strangle, the managers of Creative. Vista has been out for ages, and before that, it had been in open beta for over a year. And these X-Fi's are expensive things. So if they are too lazy or just too incompetent to get a fully functioning driver, it would just annoy me too much.
I am assuming when some of these big games, with DX10, release in the next year or so, that more people will move to Vista to play them. So I'm guessing things will be more stable by then.