The catch is you must own a copy of Photoshop CS3 or higher to qualify for the limited time pricing of $9.99 per month (sign-up before December 31, 2013). They lost me at that requirement, had they not required CS3, I would have signed up as soon as I was able to. This still may be great for customers that have chosen not to upgrade from previous versions of PhotoShop.
Into the cloud?
Adobe just announced Photoshop and Lightroom for $9.99/mth. If you don't want to lay out the cost of the software in one lump sum, this may be for you.
I personally have no interest in laying out what Photoshop costs up front, however I may take them up on this new offering once I read the fine print.