Okay, so their officially not giving it away for free--officially, they put up serial numbers so their customers can still install the software after they take down the activation servers, but everyone knows it's just going to be used to get the software for free.
Come to think of it, though, $50/month for the entire CS isn't a bad deal. It looks like that includes upgrades to CS7 whenever they become available. Over 2 years (rough average between CS releases), that's $1,200, but you get access to over $2,500 worth of software. If you only use (say) Photoshop, that's $20/month = $480, compared to just buying the latest Photoshop for $700. (I really wish I had enough use for it to justify paying for it.)
Or you could just pirate it.