The third AES conference is next week. I hope this gets addressed there. If
they say there that yes, definitely, there will be two algorithms, then so
I wonder if rather than explicitly picking two, they might use the Miss
America strategy: name the winner, but remember the first runner up.
In the event the winner is unable to perform her duties (i.e. the
cipher is broken) then the runner up steps into her shoes. Same idea
as president and vice president.
Of course it is a judgement call as to when a cipher is broken.
It's probably not going to snap like a brittle twig. Rather, there may
be some attack found that makes people a bit uncomfortable. Is that
enough to switch or not? It may be a tough call.
All in all the two cipher approach seems problematic to me.