Here are a few random links with information about Raspberry Pi cases.
- Rpi Cases Wiki Page - as of now it has two lego case designs, including the Lego Digital Designer file for one of them.
- Raw measurements from one of the beta boards
- Two different GoogleSketchup models based on the above measurements
- Perspective corrected images of a beta board
Using the lego case model above as a starting point, along with the measurements from the other links, I'm going to try to work up my own Lego case.