What about always returning the results. Granted, when sys.exit is run
there will be no results returned, but then nothing to get the results.
If we divided in two functions, would one be unittest.main and the other
unittest.nonExitingMain? Sounds ugly, but OK if no other better way is
possible.

I personally believe that main should not hijack the current interpreter
with sys.exit at all, but I understand that behavior is not changeable
at the moment (is it?).