Great note from Astrobiology last Sunday on the recent spate of "superEarth" discoveries, including the find of a single system that includes at least three near Earth mass planets. The system is located 42 light-years away near the constellations Doradus and Pictor. While the planets have short orbital periods, all less than 20 days, they weigh in at only 4-9 Earth masses.
"Using the HARPS instrument at the ESO La Silla Observatory, they have found a triple system of super- Earths around the star HD 40307. Moreover, looking at their entire sample studied with HARPS, the astronomers count a total of 45 candidate planets with a mass below 30 Earth masses and an orbital period shorter than 50 days. This implies that one solar-like star out of three harbors such planets - a finding may help astrobiologists understand the potential for habitable environments in the Universe."
These discoveries make it near certain that the holy grail of planet hunting, a near Earth mass planet in the habital zone of its star, will be found in relatively short order if the implications of these observations bear out as expected.