I'm pretty sure that US MD programs do not accept the January 2010 MCAT for Fall 2010 admission. However, I did hear of one person that was an exception to the school's rule that he was admitted into... But he had already taken a September MCAT and the school allowed him to submit his upcoming January score.
University of Maryland: What are the oldest MCAT scores accepted? The MCAT can be taken no later than the fall of the year preceding the desired year of entrance and must be taken within four years of the anticipated date of matriculation.
It is a requirement of the Albert Einstein College of Medicine that all applicants take the MCAT examination not later than September, preceding the year of matriculation. All MCAT administrations are computerized. For questions, contact: MCAT Program Office, P.O. Box 4056, Iowa City, IA 52243. For questions about computer/CBT registration and test administration contact: The MCAT Care Team, AAMC, Section for Applicant Assessment Services, 2450 N Street, NW, Washington, D.C. 20037.
For the class entering in 2010, MCATs older than 2006 will not be considered.
Applicants will receive a preliminary review of their application only after receipt of MCAT scores.
Applicants should keep in mind that all documentation, including MCAT scores must be received not later than March 15. (The deadline for the combined MD/PhD Program is December 1.)