Ah, here ya go:

http://www.adobe.com/uk/products/creativecloud/faq.html

See "How Creative Cloud Works" regards the internet connectivity requirements.

Maximum offline usage period is 180 days, basically. It'll ask you every 30 days within that time, to validate via an internet connection.

I've got a perpetual PS CS5 Ext license currently.

I like the fact that I could get affordable access to Adobe After Effects, with the new Cloud Model, for long enough to do a Poser animation project, for example... via fairly reasonable monthly payments (if I just opted for After Effects).