Renault's choice of Nick back in winter seemed to be obvious - lots of experience, about the same speed at BMW times, some extra knowledge of new Pirellis.
But now it's about the time to take directions for 2012 - regarding both new car design and drivers lineup.
Nick didn't fulfill Renault's expectations as RK's replacement, there are no really first class drivers on the market, and Kubica - who knows ?
Speed is there, no doubts, but they have to evaluate Senna in racing conditions, no other choices. If he fails, they have at least few races to evaluate Grosjean.
No comments about how they did this - IMO marcush right in that it's all about money, and for F1 team money is more important then elegance.