I just installed Vista RC1 on my Thinkpad T60 (1951-48U) and, for the first time over all the previous beta releases, Glass works! Out-of-the-box actually. And no hiccups on the install either. Apparently the WEI score was high enough to make it to Glass. Previously, I was getting a 1.0 for graphics!
I think the culprit was the onboard Intel 945GM express chipset. It's integrated video controller (950?) has the ability to dynamically allocate up to 250MB or so for video RAM.
Now a few things aren't working out the gates. External audio through speakers for example. The XP drivers from Lenovo solved this problem with pre-RC1, so I'm guessing it'll work.
Also, two drivers were recognized post-boot as part of Auto Updates: ThinkPad PM Device and UPEK biometric TouchChip. Haven't used them yet.