While I didn't get a laptop I'm happy to share my experience with using Windows Vista for two months as main development platform at work.
The first feature that I really like about Vista is:
I can finally work as non-root user!
This is a feature that the Unix world knows for a few decades. So why did it take Microsoft until 2006 to make it possible to use a normal user account in Windows? Probably it's backward compatibility. They finally solved it in Windows Vista with a very tricky solution: if a legacy application writes to a system directory Vista transparently redirects the system calls to a file that belongs to the current user. This is one nice example for the old saying: try to get it right the first time!
The next change I noticed was the integrated desktop search. You can press the Windows button on your keyboard and the search line is focused (Microsoft rediscovers the shell). Now when you enter the first few letters of a word the menu gets dynamically updated and shows only programs (and emails) that match your search. While this feature is well known from KDE (alt-F2) and is probably available for Windows XP as an extension program, I really like this feature and use it more and more to search my emails and start programs.
The desktop search is not restricted to the search bar. The Windows Explorer now features a nice little search input line on the upper right side (just like a web browser) which you can use to perform a quick full text search on your files.
Now let me count. I discovered two (2) new features in Windows Vista that I really use. But I have to admit that those two features are exactly the concepts I missed in Windows for a long time now (since I knew them from Unix) and I don't regret switching to Vista as work environment (yet).