There appears to a revolt stirring against the VSE as currently conceived, by some big names in the civil space world.

I've long thought that missions to near-Earth asteroids would be a great addition to Constellation, for reasons pretty close to those stated in the linked article (it would be new and interesting, for one, and it would be the perfect incremental test of technologies for long missions to Mars).

There is an argument to be made for substituting asteroid missions for moon missions in the VSE -- provided we can rely on the private sector to settle the moon on their own. It's certainly possible, and there have been some early stirrings of interest in it.