Yes, you World of Warcraft addicts, it's your favourite game running on the iPad. Sadly, it's not native. It's being streamed from a Gaikai server through Wi-Fi. I wonder if Apple would prohibit this kind of software too.
Gaikai is a game streaming service currently in beta. It would allow you to play games using a Flash client on any desktop and, apparently, a native client on the iPad (or iPhone, I presume). In theory, an application like this would allow any kind of game to be played in the iPhone OS without going through the App Store payment system, something that is not going to make people in Cupertino happy.