A paper just came out a few days ago on the astrophysics preprint archive which discusses the past, present, and future of planetary microlensing searches. Here is the title and author: Microlensing Searches for Planets: Results and Future Prospects B. Scott Gaudi Department of Astronomy, The Ohio State University
According to the author, the number of extrasolar planets found via microlensing has been increasing even if the results have not been published, yet. Specifically, he said: "With the recent MOA upgrade, the rate of planet detections has increased substantially. From 2003-2006, six planets were detected (four have been published). From the 2007 bulge season alone, there are four fairly secure planetary events. This rate can be expected to increase modestly as analysis techniques improve, and so the next several years should bring of order a dozen planet detections."
Microlensing searches already strongly suggest that approximately a third of the galaxy's single M dwarf stars have ~10 Me worlds between 1 and 4 A.U. These new discoveries should help shrink the large error bars associated with this statistic. After decades of ignorance and speculation, we are making great strides toward pinning down the value of Fp in the Drake equation. Very exciting!