Adobe is moving their CS products to a subscription-only model, which is bad news for those of us who use CS extensively but don't upgrade every time a new version of CS comes out. You must have a subscription to use CS products after CS6 and will need to log in periodically in order to retain access to the software. If you do not log in, your software will cease to function.
There is an online petition asking Adobe to reconsider. They would like another 6700 or so signatures to reach their goal of 35,000.
Even if you have CS6, are happy with it and can't see ever needing to upgrade, there's no guarantee that CS6 will continue to work as OS's get upgraded. I was happy with the feature set of CS3, but upgraded to CS5 when CS3 didn't work well on a new OS.
Details about the changes here: http://www.adobe.com/products/cs6/faq.html