Surely they can develop the engine initially? Plus they always find holes in the rulebook to "address power issues".
What? Like the current engines? lol.
They will give them all a set of blueprints to all build the same engine, they all will, then they will be frozen for 5 years, with the small exceptions allowed to tweak the best engines to slow them down so they dont have a performance advantage over the rest, and then everyone forgets about them.
The FIA have openly stated that they would like a single engine/drivetrain setup in F1 (it was one of the drivers behind the planned breakaway last year wasnt it?), but they didnt get it that time. So instead they ensured that only the teams who signed with Cosworth would be considered for new teams on the grid, giving them nearly 50% grid coverage with the same engine. But then that didnt work as the teams proved to either be a bit poo, or go off and sign deals with other companies (Lotus/Renault). So, the next tactic is to roll out this new cake that has "green" and "cost saving" icing all over it, and sprinklings of "loads of new manufacturers will join in", when in actual fact underneith is just another single engine series ploy...
Reading into this a bit more though... there are some interesting names on the "opposed to this idea" list.. including Bernie Ecclestone, who owns the rights to a certain "GP1" series name... and Ferrari and Mercedes, big players in the sport with lots of engine customers who have before supported a breakaway series...
Chances of us all sitting down in March 2013 to watch the opening race of the GP1 World Championship?