ICANN probably can't
The problem that I see is that ICANN has no transparency or accountability at all. They seem very secretive, and often do things that make one question their competency. All this makes me want to not trust them with full control of the root domain, even if it does put me on the same side of the question as idiots spouting nonsense about Iran taking over the Internet.
Also, as another poster pointed out, the fact that outfits like Apple, Google and Farcebook are in favor of the takeover should give one pause. Perhaps they have pre-bribed ICANN to do their bidding? I smell something fishy here.