Take a look at this:

http://www.physorg.com/news74874827.html

It's a press release by Lenovo and Novell on their Linux Thinkpad. 
Apparently, Intel is providing its IC design engineers with Linux 
Thinkpads and requested Lenovo and Novell supply them.

With this sort of backing and commitment, I'd say you should get a Thinkpad.

Ken