This peek at Uncharted 2 machinima support looks pretty good. Much nicer than Spore GA in many ways, but it doesn't seem to have built-in, high-level scripting support. Probably lower-level mods could cover in some ways.
I still think high-level machinima is much more the future of home animation than traditional tools like, say, Blender. I guess that's part of why the Blender Game Engine seems so important.
Got to make it easy. Simulate and automate. That's more approachable and, in the end (probably sooner than later), likelier to be more realistic than than expecting people to do all that stuff manually.