The overall motivations of the company are irrelevant, what matters for antitrust concerns is marketshare plus using that marketshare as leverage to own other markets.

Apple gets away with things like the 30% content tax on their devices because they don't have the sort of marketshare Microsoft enjoyed. In a world sans-Android and with the iPhone on all the major carriers, that would soon change.

And sorry, I don't believe WebOS or WP7 would factor into the conversation even if Android died (and I say this as a WP7 fan). WebOS in particular is all but dead at this point.