This is an issue where many are being vocal in their declarations of how awful it would be for the sport if the result goes against Ferrari. There is merit in this; no one wants the courts to decide who wins, we want wheel to wheel racing and this season provided it in spades. Bernie Ecclestone has said that he will consider retiring if the FIA finds for McLaren.
Personally I hope the decision stands as is, as it will put people off and give the usual suspects the opportunity to moan about how it all unfair for them (I'm looking at you Ferrari). However there is an important question to ask here; what would people have been saying if this had happened in the 3rd race of the season?
The rules have to be applied rigorously and fairly no matter when and no matter who. On this point McLaren are dead right. Why should it make a difference if it is the last race on which the championship hangs? Simple answer is that it should not. If the same potential infringement of the rules had happened in earlier races no one would have made such a fuss if points were docked and drivers were promoted and in the end it could still have affected the driver standings at the end of the season. People are perhaps too worried about the 'show' and not enough about the sport.
On the other hand perhaps McLaren should have found a way to broach this issue and at the same time disavow any interest in having the title, only in clarifying the rules as they stand.
*DISCLAIMER: I consider myself a McLaren fan and have little regard for Ferrari