While the bandwidth has gone up, they now charge a price per request to their servers. They said this is a decrease in cost for 70% of their customers.
But it's an increase for guys who were basically using S3 to serve as a way to get their web pages to come up snappier by having S3 serve their many requests for small incidental images. Reddit, for example. They were nickel and diming S3 (well, really $0.00001 and $0.000005-ing), of course totally within the terms of the service, to Amazon's chagrin. Even with the new charges though, it's a great deal for that kind of hosting.
I just started using s3 for a video site I'm launching next week and it's awesome. So far it has cost me pennies (literally)!