The re-introduction of a private engine manufacturer was pretty important.

I've always sensed that having private teams buying engines off of manufacturers (i.e. Williams Toyota) often had negative side effects (e.g. Williams being forced to run Nakajima). I believe that in the past, some teams running Ferrari customer engines required the revs be turned down.

So it's not such a bad thing that Cosworth will have a pretty big foot in the door of F1 again. In an ideal world, all the engine manufacturers would be seperate to chassis builders.

Of course, as usual, the FIA's methods are questionable at best.