The mapping class group of a manifold is the group $\pi_0 Diff(M)$ of components of the diffeomorphism group. There are several variations: oriented manifolds and orientation preserving diffeomorphisms, etc.
I am interested in finding out if we know any sorts of general properties of these groups. Are they finitely presented? finitely generated? ... ?
The mapping class groups of spheres can be identified, via a clutching construction, with the group of exotic spheres one dimension higher. Via Kervaire-Milnor, which relates these these groups to the stable homotopy groups of spheres, and the fact that the stable homotopy groups of spheres are finite, we know that these mapping class groups are finite. However this uses a lot of heavy machinery from surgery. The general case seems far from obvious (though maybe there is an obvious counter example out there?).
I would also be interested in statements about the higher homotopy groups as well.