Not the previous Boeing proposal, but a much more evolved one.
A medium sized space station placed at the 2nd Earth-Moon Libreation point (EML-2), a gravity well in space on the far side of the Moon, that would serve as a jumping off point for lunar and deep space missions. EML-2 is also the same gravitational stability point where the James Webb Space Telescope would be located. Spacecraft would be assembled in low Earth orbit then transerred and/or refueled by space tug or tankers. A re-usable lunar lander is part of the proposal.
Boeing & Lockhees (US), EADS Astrium (France), Energia (Russia), MDA (Canada), Alenia (Italy) and MHI (Mitsubishi Heavy Industries, Japan.)
Lots of pretty pictures & info -