I was shown this website in my class yesterday. Photoshop.com is a good way to manipulate photos without having to learn how to use Photoshop. It has enough tools, gadgets, and doodads to keep you busy for quite a while. While it does not completely replace the need for Photoshop, the on-your-computer product, for most of us it probably does everything you need.
I think Photoshop.com is a model for what others are saying about the future of computing. Yes, you will have a computer (of some sort) with an operating system (of some sort), but the software will be out on the Internet. This is increasingly what is happening. It will be interesting to see how large software sellers like Microsoft adjust to this new way of thinking.