My thoughts exactly. I cannot help but think there's a rather big opportunity for HW companies here...
I built the laptop I'm typing this on out of parts from three different Thinkpads because I wanted a 64-bit machine with a trackpoint and a high-quality 4:3 screen and nobody made one. About one in four of the programmer/IT types I talked to about it agreed that was a good use of my time and money.
The current specs are:
Display: 15" IPS panel, 1600x1200, matte
CPU: Intel T7700, upgradeable to T9500
GPU: Nvidia QuadroFX 570M, 128MB
Memory: 8GB DDR2 dual-channel @ 667 MHz
Disk: 320GB 5400RPM, hacked BIOS supports SATAII
Optical: DVD multi-burner
I'm not done. Planned upgrades: Display: QXGA (2048x1536) panel, when I can find one for less than $400
CPU: If something Penryn shows up cheap or free, I'll put it in
Disk: An SSD, obviously, perhaps with a hard drive in the optical bay
Battery: I'm betting there are some modern cells with higher capacity I can put in the old shell
Pretty much everything that can be done with these has been done by somebody on http://forum.thinkpads.com, so it's pretty low-risk if the idea of a semi-custom laptop appears to you. 4:3 T61 motherboards and QXGA panels are rare and often priced higher than you would expect, but the rest of the parts are cheap and easy to come by. Careful ebay shopping may procure the rare parts for a more reasonable price.