I once tried to combine chiptune with orchestral and it was direct rejected because the chiptune and orchestral elements "didn't fit together" or, to quote the actual letter, "Synths and orch is a cool combo, but the sounds aren't gelling at all, production-wise." I agree with that for the most part now, and it lead to the creation of a replacement mix (The Kirb Reich) which I heard was also equally popular with the joojs, so it's all good.
http://remix.thasauce.net/song/RTS0271/
Back then I wasn't good enough to set any kind of chiptune precedent, I might give chiptune a shot one day, but it really has not been a part of my repertoire.