[summerlight]

Probably Apple is hoping the entire Apple ecosystem not to be defined as "a market" in terms of antitrust laws. I am not sure if the Justice Department will agree with it though; we'll see.

If it's defined as a market, then Apple will be surely in trouble but enforcing Apple ID alone doesn't make much differences from the current situation as it always has been doing similar things for web browsers, music apps, app store itself etc. So it's pretty natural to enforce this policy for Apple; no additional risks but only benefits.