That's pretty cool. Although (looked at trial) it has no where near to the abilities as Photoshop, just a lot of the features that most users would want e.g. removing red eye or color balancing. But for the more advanced users who want to do things like work with photo layers this program doesn't look like it's able to do that.
I never thought I'd say this but every day it seems like the prophecy of your OS and programs running off the Internet seems to be getting closer.