I saw that a few days ago and tried out the demo - looks like a great tool for photographers.
I also saw an article yesterday about Adobe's terms of service for Photoshop Express, where they basically claim the rights to use any photos uploaded to their service for whatever purpose they want, including selling them. Jim Goldstein over at JMG Galleries wrote a great article
that explains it in detail - you might want to check it out.
Adobe has already acknowledged the problems
with the TOS, and is supposed to be revising it.
I'd wait to sign up for it until the TOS has been fixed.