It is a strange situation, the drivers, the teams, the circuit all have contracts, so who has the final say?
I think the FIA will pretty much dictate what happens.
What the public have to understand is that F1 is one of, if not the most, money oriented sport in the World. Money is pretty much everything in F1. It is an elitist sport if I ever saw one. In fact money is so important in F1, that if you don't have enough of it, you can't enter it. This goes for drivers, teams, sponsors, etc.
In most sports, if you have the talent/ability, you will get accepted into a team/event - football, tennis, athletics, etc. In F1 however, you can be the most talented driver in the World trying to break into the sport. If you are bringing no money into the team, then the team is likely to hire a lesser driver, who is bringing money.
So, when Bahrain is offering a fair whack of money to host a GP, the F1 circus will most definitely go there, UNLESS there are extreme circumstances.
Earlier this year, there was just such an extreme circumstance, where Governments around the World had advised their citizens not to go to Bahrain due to serious unrest. Unless something extreme happens in October, this GP will definitely take place...with or without Mark Webber.
I'm just surprised to hear that Mark Webber still believes that the GP won't take place. I can only think that he knows something that we don't.