Glad they are offering the service.
Though personally I'm not a big fan of this form of isolated gaming network. however, taking advantage of cloud storage, achievements and stuff is great :)
PSN, Live, WiiWhatever, GameCenter, GooglePlay
C2 can only support that which is through the Browser. i can garuntee that this is not a webapp. We will have to wait for CocoonJS to support it. Then wait for either Scirra or Ludie to work on the CJS plugin :(