I don't think apple could do anything to the dev team legally. It's their devices and if they want to mod them, they can. If they want to distribute the mod, they can. It would be like ford saying you couldn't put an aftermarket exhaust on your mustang, it's not theirs to say what can and can't be done. Now niether ford nor apple would have to honor any warranty. Now, I believe apple has said that in their opinion jailbreaking is illegal, (although I'm not sure exactly on what grounds they think that, but I would assume it would have something to do with piracy) but they haven't taken any action on it. I think the reason that is, is because they would probably lose, and they don't want to set any precedent on the matter at this point. Just a guess though.