From what I recall from reading and watching a bunch of those recent hands-on previews, the humans can apparently stop the self-destruct if at least one of them can get to the Predator before it goes off and deliver a killing blow, which sounds like it could create some fun and potentially really tense last-minute situations where you'll have to decide whether you think you're close enough to get to him in time to stop it (and risk getting blown up for sure if you're wrong), or just say to hell with it and try to get out of there.