Who's next, and whodunnit?

The news this week that Toyota have pulled out of F1 with immediate effect and that tyre supplier Bridgestone will do the same at the end of 2010, both citing economic pressures, has sent shock waves through the sport. Who will be next?

Speculation is rife that Renault could walk after the French manufacturer called a board meeting in Paris yesterday, with its continued participation in the championship on the agenda. 

Renault F1 is playing down the potential ramifications of the meeting, and in fairness the team might do better to rebuild its tarnished reputation rather than bow out covered in you-know-what. Plus, to sign Robert Kubica and then cancel everything would be a capital offense. 

I really hope this rumour isn't true, and I'm 75 percent confident it isn't.

Meanwhile Ferrari, now one of only three manufacturers left in F1, left a cryptic message on its website likening F1 to an Agatha Christie whodunnit, suggesting one team was trying to kill off all the others.

Now that Toyota is gone, the Sauber team is free to take up the 13th and last grid slot for 2010. The Williams team had opposed the participation of a 14th team.