There are a variety of reasons I personally would never get one. A couple of them are presented in @Austinlad‘s link. One is Apple’s quick obsolescence cycle, coupled with the fact that the iPad2 isn’t that big an upgrade (unless the chat-cam is vitally important to you), so if you are set on getting an iPad, see what the iPad3 has to offer; it’ll probably be out well before Christmas.
Another is that it’s a bit big for what I would use a tablet for; I prefer a 7-inch form factor. Then again, most of what I would need a tablet for is stuff I can already do on my Droid X, though it would be nice to do the same stuff without draining the battery on my phone, especially since I don’t have a landline. I would pretty much use it as a combination e-reader (I have many PDF-format RPG books, and those are 8½×11”; not a fun read on a 4.3” screen) and game rig. For actual computer-type stuff, I have a nice 13” Toshiba laptop with a battery life of over 6 hours, a weight of under four pounds, and far more computing power than any tablet.
I find Android to be better than iOS anyways, and when you add that to the fact that Apple doesn’t offer the sort of hardware I want (only one model really) while the Android side does, if I were in the market for a tablet, I would look elsewhere. I might change my mind if Apple offered a 7” model for under $400.
Your desires may be different from mine though. Just as opinions differ, it is hard for any of us to say if an iPad2 would be a worthwhile purchase for you. It really wouldn’t be for me since that is a lot of money to shell out for the convenience of carrying my RPG sourcebook library with me, especially since those PDFs are already on my laptop.
@JLeslie There is a reason I got a 13” model. Many people I hear that complaint from have something a bit larger and almost twice as heavy as what I have that has no more processing power and about half the battery life. An added bonus is that, unlike a tablet, a laptop that is not in use is fairly rugged; I don’t have to worry so much about cracking my screen (which is safely covered my much hard plastic that is even tougher than Apple’s “Smart Cover”) like I would with a tablet.
@nikipedia Many (most?) people only use their computer for surfing the net, e-mail, and watching videos. For people like that, a tablet actually makes more sense due to it’s limited functionality; why get something you don’t need like the ability to run Excel? However, I think that people like you and I are better served by actual laptops.