  The satellite COROT will search for close-in exo-planets around a few
thousand stars using the transit search method. The COROT mission holds the
promise of detecting numerous exo-planets. Together with radial velocity
follow-up observations, the masses of the detected planets will be known.
  We have devised a method for predicting the expected planetary populations
and compared it to the already known exo-planets. Our method works by looking
at all hydrostatic envelope solutions of giant gas planets that could possibly
exist in arbitrary planetary nebulae and comparing the relative abundance of
different masses. We have completed the first such survey of hydrostatic
equilibria in an orbital range covering periods of 1 to 50 days.
  Statistical analysis of the calculated envelopes suggests division into three
classes of giant planets that are distinguished by orbital separation. We term
them classes G (close-in), H, and J (large separation). Each class has distinct
properties such as a typical mass range.
  Furthermore, the division between class H and J appears to mark important
changes in the formation: For close-in planets (classes G and H) the concept of
a critical core-mass is meaningless while it is important for class J. This
result needs confirmation by future dynamical analysis.
