I would like to see SpaceHab working on the new Moon, Mars and Beyond mission requirements. Part of that would be a new space station designed for assembly of manned deep space and moon missions.
a perhaps useful sidebar, from the Wayback Machine, a page from Beal Aerospace' old website (Andrew Beal is/was on the X-Prize committee after BA folded):
http://web.archive.org/web/20000817002608/http://www.bealaerospace.com/enginecomparisonchart2.htm
Old Space dot com story about the test of the 810,000 lb thrust BA engine, complete with a test photo:
http://www.space.com/businesstechnology/business/beal_firing_000306.html
remarkably, Beal Aerospace went from founding in 1997 to this test in 2000.