Vuforia works fine with Unity 4 and Android, however it won't compile on iOS. I get these errors in AppController.mm
/Classes/AppController.mm:370:65: No member named 'w' in 'EAGLSurfaceDesc'
/Classes/AppController.mm:781:52: Use of undeclared identifier '_curOrientation'; did you mean 'orientation'?
/Classes/AppController.mm:781:52: Cannot initialize a parameter of type 'int' with an lvalue of type 'NSString *'
It looks like the API has changed slightly and Vuforia needs an update to deal with it?