Really? You don't think Kubica has an option in the last year of his contract (which I think next year is)? I expect he'll have an escape clause, as will Renault.
My understanding is that Robert has a 3+2 deal (three years fixed, two years option) with Renault. Therefore any escape clause not connected to breach of contract would become active only at the end of next year*. So Robert will need a decent car so that everyone can see that he has recovered - and that either Renault will take the option or Ferrari/Red Bull/McLaren/Mercedes puts him in place of Massa/Webber/Hamilton or Button/Schumacher.
I would expect Robert to do a FP1 session for Renault in Brazil. That way, not only can he indicate to them how fit he is and what they can expect in terms of remaining recovery time, but Renault gets to benefit from all his feedback and hopefully improve the 2012 car with it. No need to set up tests with anyone else or put any special effort into doing a test just for him.
No need for contract-shuffling... ...just respect, a little time and some healing.
I think if Robert is fit and fast, he should set up a test at one of the top three teams (which they will be more than pleased to provide - wonderful PR helping out a wounded driver and all that), so he has a car that can show his stuff. If Renault then indeed want him back, they can pay the price he expects. Otherwise, one of the other teams...perhaps even one primarily
RED, could do some last minute driver shuffling. Imagine Alonso and Kubica. Wow...
That said, I don't think he'll be fit...just my hunch.