I am waiting for Sean to get his band of merry men up to Norfolk, after learning that Chandler has family there. Given how the country has fallen apart, Norfolk would probably be considered the nation's capital and the Nathan James needs to defend it.
And why do I get the feeling a season 3 will revolve around reuniting the country after it breaks into regional governments, ala Jericho.
Well, they can't keep milking the cure storyline forever. They found the cure pretty fast and started to distribute it only to have the labs destroyed by the sub. However the theoretical knowledge is still there and we have now established that humankind won't die out (they have enough people to form a stable genetic pool, no hillbilly inbreeding needed) so even without the cure humankind will survive.
So they are establishing an additional storyline that will be able to carry the show onwards to how many seasons they can make and it's an interesting storyline.
I just wish they'd abandon the central villain of the season .. 1st season saw them battling a russian destroyer, now it's a british sub.. what's next? A Chinese carrier? It get's a little stale and they can go so many other ways.