Another voice from one who has had the experience of attaining MR status while being a few nights short. Marriott has difficult plateaus and generally refuses to comp anybody to gold or plat, but is quite lenient when it comes to renewing its own customers.
Note to Cindi89 - Don't hesitate to call them sometime after the first of the year (maybe just after your early January stay posts) and they will surely give you the status. They probably will even if you don't call.