Update to Alternative Space Launch Proposal
A group of people in the space community have developed an alternative Shuttle-derived launch system for launching the Orion Crew Exploration Vehicle and other cargo to space. Their proposal, called DIRECT (v.2.0 just unveiled), uses existing Space Shuttle technology with more simplified modifications as compared with NASA's current baseline Ares I/V systems. Given tight NASA budgets and performance issues surrounding the Ares vehicles, this proposal might just save the Vision of returning humans to the Moon and going beyond when things come to a crunch.
It has also been argued, probably correctly, that the best approach for human space exploration would be for NASA to contract for launch services from commercial providers and utilize in-space infrastructure development such as propellant storage and refueling. This will certainly be the way to go to sustain an expanding presence on the frontier. However, given the constituency politics invested in the existing Shuttle system industrial base, an alternative along the lines of the DIRECT proposal may be the most likely near-term politically acceptable path to saving the human exploration program while preserving other important NASA programs.
(As always, comments on space policy and specific ways of implementation are my own opinion and do not necessarily reflect the views of my employer or any other organization I am affiliated with.)