I've had a T42 for 3+ years now (4 in December) and I love it. I did have a fan failure about a year ago, but I purchased the 9x5 next business day service so they came out and fixed it right away. I looked at it and I'm pretty sure it was just full of dust and couldn't spin up.
I highly suggest that you avoid Vista if you can. Its a bloated OS that will need time for bugs to be worked out and hardware to evolve to support it. XP had the same problem, but now I consider it "seasoned" well enough. If you really want to run Vista, run it on a Mac. :-)