For those on nVidia cards, the drivers released last (?) week seem to have made a big difference to my game (although my rig is a bit of an old clunker, so any improvement is a massive improvement).

Might be worthwhile checking them out.

Last week I installed version 306.96---I don't know if this version is what you referring to---, and I've seen a moderate improvement in my fps for Skyrim.

Haven't tried Skyrim with the new driver update, I just might now however.