It was too late after Elop made his announcement. Elop had killed every product they had out. Symbian is effectively dead. QT for their moble phones is effectively dead, considering that it is unlikely that QT will make any sort of progress with WM.

While he talks about "disruptive" products, they are mostly going to start from near zero because of this decision, with nothing to really market for at least a year. I'd be amazed if Nokia was able to develop anything internally OS-wise that would be of any signifigance to their industry.