… we pulled the plug and try to fix it. The problem is that
allowing epstopdf we in fact obliterate openout_any becasue
epstopdf can write everywhere.
As long as we are not able to provide a restricted epstopdf that
only allows writing to subdirectories or similar we will
unfortunately not have this feature …
So for the moment you still need to turn on
\write18 explicitly if you need it (at least with TeX Live: I’d imagine that MiKTeX will be updated with the same change). I hope that a solution can be found to provide easy to use
\write18 for a subset of ‘safe’ programs, but for the moment we have to wait.