I installed Ubuntu 8.10 as beta on my Lenovo x200 and nearly everything worked out of the box. With kernel 2.6.27 I did not expect anything else.
The only thing that seems not to work is the camera (funny though: the camera in the t400 is working without problems). Everything kept on getting more and more stable over time.
Still, for some odd reason I am expecting more from the intel video card. Still having trouble with World of Warcraft (Wotlk) because there are graphical glitches and it even freezes the whole OS sometimes. I have not tried any other game which needs 3D, but I am hoping that newer releases of mesa and the intel driver may improve things.
However, I guess that this means to wait for 9.04.
The wireless is working pretty well. Just yesterday I was downloading rather many files over short period and my internet link was fully used. That also means that the wireless connection to my AP is working rather well. I had some troubles earlier on, but they seem to be fixed or happen to occur less often.
However, I am not happy about the overall performance with Ubuntu 8.10 and I am really hoping that 9.04 will bring some improvments…