One of the biggest pushes that NASA has been up to has been building the whole Aries (aka the Shuttle-Derived Launch Vehicle) system. Of course, to build it means funding and supporting and supplying the whole space launch and industry system. Including all new contracts to do research and development and produce all new space hardware...by 2012 or so.
Of course, a much cheaper system and proposal is outlined here, in the form of the Jupiter I-V system. This setup would mean man would be back on the Moon...in five years or less. Maybe six. I would love to work on this project...at the very least, work on writing up all the neat and interesting paperwork and documentation needed. As long as I got a chance to play in the simulators every once in a while.