I like macs but not platform dependence - my kid *had* to run windows software. I wouldn't want iPad dependence, either.
I think, though, that there is a case to be made for color, real wireless, and meaningful performance. Most of the added stuff for textbooks, animations and so on, don't do a whole lot, but color adds very meaningful and sometimes essential "bandwidth" (for example, an article on color blindness). Presumably you'll be able to get all that for $50 in a few years. $500 isn't even terrible. Oh, and a reasonably big screen! We have a B&W Nook, and a color one, which are fun and nice but not good enough as browsers, which i consider the relevant format not the classic trade paperback.
Theft on iPods and 'Phones (my son lost his 4S) is huge here. I haven't heard much about the computers. A mom tells me the iPads are not allowed to go home. She hasn't heard of thefts ... just the usual abuses (like posting harassing messages without realizing they're traceable to the device ... yawn). It shouldn't take too much genius to set something up to hobble or brick missing machines. I don't know. Kids carry a lot of valuables these days. You shoud hear my rants about "essential" gadgets.... :) Oh wait, you have a 5-digit UID -- oldtimer?