Apple today released an ominous statement that the iPhone updates "might" brick SIM unlocked phones. This wasn't wholey unexpected but now there are a few clearer roads down which unlocked iPhone users are going to have to navigate. There are different hacks to the iPhone, but we'll assume that Apple is addressing not just the SIM unlockers but the jailbreakers as well.
First of all, we have to consider the seriousness of this threat by Apple. The company conspicuously didn't release the threat on their own PR webpage but through other media outlets - if that is any indication. They also didn't promise one way or the other if it would break the software. Apple, of course, knows if the firmware update will brick