I know someone who bought an EeePC 1000 with Linux and didn't like it. It was too limited and unstable. It wasn't Linux that was the problem, it was the half-baked Xandros mess that Asus used. Lots of bugs and the "simple" desktop only shows a few of the applications that are installed. The user plans to replace this OS mess Ubuntu 9.04 (Jaunty Jackalope) when it comes out later this month.
It's amazing how many OEMs do a bad job with the OSes. You get a choice of loads of crapware on Windows or a crippled Linux config. I'm glad I build my own.