Why, exactly, does Vijay need to hurry the decision? He's always waited until December (or January) to make his decisions concerning drivers because that gives him the best range of choices. Face it, if he waits long enough he might even be able to get Robert Kubica off Renault, and that's a prize worth waiting for (even if he is only a third driver in 2012 due to his curent injury). Obviously, the possibility to get or not get Robert would make a considerable difference to where Adrian, Paul and Nico end up in the final arrangement of the team.
I'd be surprised if Nico has a race contract already, even if one year makes sense for its length. It would be more likely for it to be a contract to provide a car - somewhere. More of a "we will look after you" contract than a "we will put you in our race car" or even necessarily "we will put you in a race car". How else do you explain Tonio Liuzzi not making a formal settlement with Force India or filing a lawsuit?
It means Vijay can prepare for any eventuality concerning drivers and encourage both loyalty and constant skill development. Paul di Resta's never suggested he would be anywhere other than Force India in 2012, apart from a brief period when it looked like Schumacher might retire early, and he's constantly improved his driving, so he will naturally be rewarded with a drive next season. Given that Adrian Sutil has been treading water for the last 12 months, I suspect he'll end up implicit team leader too. Nico's been improving too, so unless Adrian starts improving he should pretty much expect to need to make arrangements elsewhere. I don't think Vijay has much interest in standing still.
It's not a warm or cuddly way of doing things but so far it's proven very effective. It takes a particular mindset to thrive at Force India. This has so far been a reliable way of ensuring that drivers either have that mindset and constantly improve their abilities or are removed from the equation. Therefore, do not expect Vijay to abandon the technique any time soon.
For my predictions regarding Force India's status in 2012:
If Robert becomes available: di Resta-Hulkenburg-Kubica (whether Sutil has made other arrangements or not)
If Robert is not available and both current race drivers stay: di Resta-Sutil-Hulkenburg
If Robert is not available and Sutil bails: di Resta-Hulkenburg-some rookie (I won't even attempt to predict who)