Deployments are highly sought after...seriously. I know many people that have volunteered many times and have not been able to get a slot. Deployments are like root canals...you hear how bad they are until you actually experience one...then you realize it was not that bad. Of course, there are always exceptions...but almost everyone I know that has deployed (including myself), values the time spent in the sandbox. I would go again in a second, no questions asked.
BTW, I deployed to Iraq after dental school: Graduated May 8, 2004, came on Active Duty May 23, was in Iraq in August. This does not happen much anymore...but it happened to me....I was upset at the time. After I got back, I was glad...as I learned more than those few months in a dental clinic could have taught me.
NO, I didn't do a one year...I didn't get accepted.