Great, I am looking forward to the next OptiX release. Will this happen before GTC2014? I submitted a talk proposal and (depending on the new features of) OptiX 4.0 (?) might be interesting to evaluate before that.
The next version of OptiX will contain support for CUDA 5.5 as well as numerous bug fixes and new features (no spoilers :). Unfortunately I can’t commit on a firm release date, but we hope to get it out shortly.