I moved my main laptop over to Vista about two months ago and overall I'm really happy with the switch (I have been using Vista on my second machine for much longer on various builds available inside the company).
I really like Vista, it has major upgrades all over the place, way too many to list here. With every upgrade I not only see the major changes but I tend to pay attention to the smaller aspects that change how I work everyday. Some of the smaller things that I have noticed are:
I know a lot of these seem trivial but I've been really impressed by Vista. One of my machines has Windows XP on it and every time I swap to it I miss Vista type features.