I just turn off trackpads, I'm not interested in that kind of input device, and any space dedicated to one is wasted to me. I use nibs exclusively (which essentially restricts me to Thinkpads).
My arms rest on the body, the last thing I want is for it to be a material that leeches heat out of my body or that is likely to react with my hands' sweat and oils.
That alone is already very compelling for me (no noise, no fan to wear out). Then on top of that it has:
* Amazing battery life
* Great performance
* The best trackpad in the world
* Bright, crisp screen
The only downsides are the lack of upgradability and the annoying OS, but at least it's UNIX.