Vista will OUTPACE XP IN ADOPTION RATES...
It might, because XP was released when its predecessor was not obsolete unlike Vista which is replacing a 6yo operating system. But on the same end I know my office has no intention of upgrading for *at least* two years. We have far too much going on to worry about Vista and when MS drags their feet on letting antivirus companies have the access they needed to get products out for it.