This doesn't sound very promising. I did a quick search for people's experiences with OTG on the Optimus G and found no success stories. Do we have any indication that the hardware is capable of host mode? Before anyone except reviewers had an N4, there was an implicit assumption that the answer was "yes," but I'm not sure anyone had any actual reason to believe that.
It's not a deal-breaker for me, as I'm seldom in a situation where I can't plug into my computer to save/load files, but I was looking forward to the convenience of just carrying a thumb drive around for that purpose. Oh, well...