I've upgraded my T60 to Ubuntu 7.10. the main thing I noticed is that now hibernate/resume works as it should. Ubuntu 7.04 had a nasty bug when sound did not work anymore after resume. This has been fixed now.
And since I have an ATI x1400 card inside I also wanted to test the latest ATI drivers that support composite so compiz-fusion can work. But the drivers have a bug which prevents a notebook to go to hibernate mode. So now, until ATI releases new driver's, I'll not be using compiz-fusion since hibernate is more important to me. And for me these compiz gets in a way after a while, but it has some very nice graphics effects.