The story I found this morning about the Kindle DX pilot program at UVA reminded me that it wasn't the only pilot last fall. I've found reports on several of the pilots, and I'll write them up as I get the chance.
Princeton University released the final report on their ereader pilot last month. You can download it here. The results were mixed, but generally the same as that of UVA. The Kindle doesn't make a good digital textbook. It's very good at displaying text, but like most epaper based devices it falls far short of the annotation abilities most students require.