I absolutely love my Kindle and recommend it without reservation to anyone who loves to read. That said, some of the other posters may be right in that there could be a dearth of textbooks available for it. I don’t know that for sure, never having had occasion to research the issue. Also note that someone mentioned the fact that it reads PDFs; that’s true, but it’s NOT a particularly good reader for PDFs IMHO. It displays one PDF page at a time, which makes for some tiny text.
One of my favorite features, BTW, requires the 3G version. I love that whenever I have the Kindle with me, if I spot a good looking book on a shelf somewhere, I can instantly power up the Kindle and download a free sample of that book, right then and there. The same can be done with the WiFi version, of course; you’ll just have to wait until you’re somewhere with WiFi connectivity. The free-sample feature has saved me a ton of money. I’ve read so much that I’ve gotten extremely selective on quality of writing, and being able to get a free sample saves me from many a purchase of a book I’d never finish.