Is Airplay mirroring just clicking the Airplay icon on the taskbar? If so I think all apps should be able to do that. At least all the apps that I have tried to show on my tv actually showed up on my tv so far. Note that this is different from when an app supports Airplay natively, where it will use the full tv dispay. With mirroring, I get lesser (with landscape iPad) or more (with portrait iPad) black bars to the sides of whatever is being mirrored through my Apple TV...
