The Collaborative International Dictionary of English v.0.48:

pan out \pan` out"\ (p[a^]n`out"),
   1. v. i. To succeed; as, the project didn't pan out.
      [PJC]

   2. To turn out (profitably or unprofitably); to result; to
      develop; as, the investigation, or the speculation, panned
      out poorly. [Slang, U. S.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

pan out
    v 1: be a success; "The idea panned out"
    2: wash dirt in a pan to separate out the precious minerals
       [syn: pan, pan out, pan off]

Moby Thesaurus II by Grady Ward, 1.0:

25 Moby Thesaurus words for "pan out":
   attend, become of, click, come about, come of, come off, come out,
   develop, end, ensue, eventuate, fall out, fare, follow, go,
   go over, issue, prove, prove out, prove to be, result, terminate,
   turn out, unfold, work out