FIA are now in exclusive talks with Cosworth in the supply of a alternative, cheaper, powerplant for F1 teams.
http://www.autosport.com/news/report.php/id/72324
http://en.f1-live.com/f1/en/headline...05092724.shtml
Apparently this will NOT be a mandatory engine for all teams. McLaren can still use Mercedes engines, Renault can use their own etc. The Cosworth will be a "standard" engine for those without manufacturer backing. Which in the wake of Honda's pullout of F1 seems to be a good idea.
I personally would LOVE to see Cosworth back in F1