I seriously doubt they will make another season....
If Jack lives, it will just absolutely kill the accuracy of what has been going on. It would continue everything and they left a lot of things unanswered...which makes you realize there is another season but if Jack comes back healthy as ever, then it just will turn alot of people off.
His daughter just volunteered for the 'experimental' treatment and the FBI chick just went loco. Of course there is another serious and it won't be that unbelievable. I saw the 'experimental' treatment thing about 7 weeks ago, that should not have come as any great surprise. I also fully expect the next series to start with the fact the 'experimental' treatment did not work and Jack is indeed dead. So endeth the Senate hearings.
Oops, until another major catastrophe occurs of course in which case he will be unexpectedly 'raised from the dead' and him and the FBI chick go on a mayhem trail.