I've been playing it on and off since about October. Well worth a look and it's the sort of thing where you can just jump in for 15 minutes and then leave it again. It should be free to play but with the option to purchase "gold" which in turn gets you more experience/credits per match and lets you buy some fancy tanks that don't really have any massive advantages over the ones you work for. Also rewards teamwork in a big way - definitely the sort of thing that deserves an arrse clan.
Just downloaded it (coz it's getting a bit tame on here of late) Any hints or tips? even sensible ones??