Have you received any acceptances or just waitlist spots elsewhere? If you are accepted somewhere and you withdraw to reapply to Maryland next year, it would be idiotic. You are in no way guaranteed an acceptance at Maryland next year (in fact as a re-applicant you almost have a higher hill to climb - and I speak from personal experience). Its almost the same for the waitlists - if you get in somewhere, you should go rather than risk not getting into Maryland or anywhere else. Without an acceptance from Maryland in hand, the question should not be "would I rather go to Maryland than any of these other schools" but rather "would I rather not go to medical school at all if I can't go to Maryland?"
I would advise against applying early decision. If you were not accepted this cycle, applying early decision will not help your application at all as they've already indicated you're an immediately desirable applicant. If you apply again, apply regular cycle, and be prepared to discuss at an interview what, if anything, has changed to make you a more desirable applicant.