I have XP Pro optimized and working very well presently. That said, my plan is to wait until the first major "rev" of Vista is released in what (guessing) may be a year or more. At that point I will definitely move from XP to Vista. In the meantime, as apple developers prepare more native apps to run on the new Intel MacBook/MacBook Pro and (hopefully) rosetta becomes a thing of the past, then I'm a buyer for a new MacBook or MacBook Pro. If virtualization becomes a stable and viable alternative, and the prospect of running both OSX.x and Vista together on the same MacBook Pro becomes real, then I will most probably go that way.