I get the feeling, from the comments made on the F1 forum, while evasive, Whitmarsh did say that he had no plans to get rid of Button for a long time to come, so it is quite possible that they were already discussing a long term deal. Button has proved this year, that he is more than capable of driving a front end car, that the brawn year wasn't a flash in the pan, and that he has the maturity to hold the team together well, while his teammate is having what can only be described as a bit of a dog.
McLaren now have exactly what they need, a solid dependable driver, that can be up at the front, scoring valuable points, even winning races when the opportunity presents itself. And a younger, more impetuous driver, that will benefit from his teammates experience and calmness, while also bringing in the points.
Trick now is to fit hamilton with warning lights and bumpers..