It looks like the most powerful radiotelescope yet devised is to be built on the Moon, under plans being put together by NASA for its 2018 lunar mission:
NASA looks to a new frontier by building telescope on the Moon
"The most powerful radiotelescope yet devised is to be built on the Moon, under plans being put together by NASA for its 2018 lunar mission. Mike Griffin, the head of the US space agency, said the construction of a telescope is being “factored into” the mission. A radiotelescope on the Moon would offer astronomers and physicists an unrivalled opportunity to see farther into the cosmos than ever before and in more detail."
...also some good news for those of us who would like to see NASA get out of orbit a bit more:
"Dr Griffin is convinced that NASA’s concentration, since the six Apollo Moon landings, on the space shuttle programme and the International Space Station was a mistake, because they were limited to orbiting Earth rather than aiming beyond the home planet."