Some info on this from an EA representative:

EA Mobile is pushing the boundaries on the iOS platform.  After the successful launch of FIFA 11 on iOS, EA Mobile is introducing innovative tech capabilities reaffirming FIFA as the number one football franchise on the App store.  Players will be able to link their iPhone to an iPad 2 via Bluetooth. Once connected, the iPhone become the game controller and allows for enhanced gameplay on the high res iPad 2 screen.  This takes the FIFA experience from a single player mobile game into a true, vivid, multiplayer experience.

Sounds exciting! Hopefully we’ll see the same thing from EA and other developers in other games as well.