If you're going to retake before Jan 2015 - very soon - then I would do nothing but get yourself set up to publish at your research institute, and absolutely work to dominate the MCAT. Like it or not, the rest of your gap time will be at least partially dictated by the score you receive.
Of course you should look into other interests as well. Clinical volunteering is always good. But I think doing well on the MCAT is going to be really significant here.