Plus, Amazon doesn't say "unlimited" and then turn around and say "haha oops there are pretty low limits after all!" when you get Slashdotted. Their pricing is transparent. The cheapo shared static hosting providers are now officially the living dead.
Sorry if I sound naive about the term 'unlimited' here, but what are the implications of your comments [1]? I see that S3 does not offer a flat-fee, 'unlimited' model at all [2]. In fact, if my math is right 5 bucks only gives you $5/($0.1/GB) = 50GB of data transfer (forgetting about the other costs).
Edit: I didn't see the 'data in' vs. 'data out'. I think it's actually worse: the first 1GB out free, and 33.33GB extra at $0.150/GB. So 5 bucks doesn't quite give you 35GB!
[1] My guess is that with this 'unlimited' you'll never get even close to 50GB of monthly data transfer.
Unlimited hosting for 5 bucks? How's world class with a CDN for 45 cents?