IPython v 2.0.0, vanilla configuration.
Previous to setting IPCompleter.greedy, I get filename tab completion inside of quotes. Afterwards, I don't:
In [1]: open("/tmp<TAB>
/tmp/randomfile1
/tmp/randomfile2
...
In [2]: %config IPCompleter.greedy = True
In [3]: open("/tmp<TAB>
Now I just get an error beep.