I've been eyeballing a laptop / notebook for a while now, but have never made the jump. I noticed that EVERY laptop in the ads I read contained Windows XP Media Center Edition.
In case you haven't done a lot of research on the subject, I know of several soundcard companies that explicitly state that they WILL NOT SUPPORT Windows XP Media Center Edition. Why? It's because Windows Media Center Edition is extremely picky with the type of hardware that can be used with it.
This may come as a shock, but the Windows Media Center Edition is no better for home recording, DVD watching, or any other task that we would assume a computer with such a title would be good for. I've recorded over 100 albums with Windows XP in the past 4 years. My brother had edited many DVDs with his Windows XP. I've watched numerous downloaded documentaries on my TV using Windows XP and a video card with TV out.
So the point is that Windows XP Media Center Edition is a real pain for people who intend to do some home recording. Please check with the manufacturer of your soundcard to see what they say about Windows XP Media Center. More than likely, you won't have any luck with Media Center.