After a lengthy consideration, the Simple Public License (SimPL) has been added to the list of approved licenses. The concern was that because the SimPL is a reciprocal license, it could create its own ghetto of code unusable by any other project. However, because it contains language that allows relicensing under the GPL v2.0 or v3.0, this will not happen. That should give developers the confidence to adopt the SimPL without fear of marginalization.
Thanks to Robert W. Gomulkiewicz for writing it, and his student, Jim Sfekas, for submitting this license.