Microlensing: Prospects for the Future
  Four ongoing microlensing experiments have produced important new results but also big puzzles, the major one being that the expected classes of lenses cannot account for the observed distribution of time scales. I discuss future experiments that could resolve these puzzles. By far the most important would be to launch a parallax satellite into solar orbit. I also discuss a number of non-dark-matter applications of microlensing, including searching for planets, measuring the rotation speeds of giant stars, and imaging a black hole at the center of a quasar. 
Andrew Gould