You mean like MS did at Benetton?
There are reports in the German media that claim MS extended his contract to 2013 and has an option for 2014. Couldn't be any better for Mercedes.
While based on recent progress I wouldn't be very surprised if Schumacher continued in 2013, I'm doubtful contract has been signed this early. Surely MS wants to see if MB makes any progress at all during 2012 and MB wants to see if Hülkenberg/di Resta/whoever matures into a real contender worth of getting hired?