It seems like everything that I want working on my T40 is working - with a bit of work on my part:
ACPI - Suspend works with gentoo-dev-sources (2.6.1). There are some problems with the e1000 module when it comes back up - sometimes I lose my connection. cpufreqd is a cool program.
Sound works well with alsa and - unlike my T23 - there are no problems after I come up from suspend. Not sure if this is because I was using APM with the T23.
The wireless card works with the ndiswrapper driver (wrapper around Intel's proprietary Windows Centrino driver). I hate this, by the way. It works well, and the guys and girls who wrote the wrapper should be commended, but Intel really sucks for the Centrino driver mess - not worth going in to.
Graphics driver works well. Well enough to play cube. I am using the kernel driver, not ATI's proprietary mess.
Laptops still have quite a way when it comes to free operating systems. I am not blaming the developers - the companies that make the hardware are still so protective over their proprietary bits.

In other news, I played with LTSP a bit today for work. K12 is great. Clusterknoppix is great. I am so lucky to have all of this cool shit to play with. Though, I can't help but think with a bit of polish these projects could all come together and make a really kick-ass terminal server solution. Automatic clustering, terminal server, simple gui tools...