The astronauts keep the orbiter, you have an HLLV for BEO, and EELV type strap-ons. That would have been a true space transportation system.
Since the Shuttle is dead, I don't think it would be replicated for use in parallel with an existing HLLV because the large payload bay (a huge driver of the Shuttle's design) would be redundant. A reusable, landable, smaller craft might be extremely useful though, combining a large cabin and crew size (like the Shuttle offered), perhaps with a robotic arm, a much smaller payload bay. Basically the other route being pursued by Sierra Nevada with their Dream Chaser.
Here's a nice study on fuel depots, though it doesn't ask whether a near Earth asteroid mission really accomplishes anything if we aren't going to use the asteroid.