a lot of school will not consider your january mcat score for entering fall 2009...
This has been my experience. Virtually all schools have rules stating that they won't look at any MCAT score after September 2008 (and in some cases it's August). I have a very low PS score, but have managed to get 6 interview invites; I decided to retake the MCAT in January anyway, on the very slim chance that it might help me somewhere. Also, I thought it might help me get off waitlists, if I ended up there because of my MCAT score.
When I emailed all my schools after the test and very politely requested that they wait to make a final decision until they had seen my new score, I was FLOODED with negative responses, and haven't gotten a single positive response. On the other hand, the schools where I have interviewed (including CMS) seem very interested in seeing the new score, so it may well help me at those places.
There are a few schools that interview unusually late (including CMS, which interviews through May), but they are the exception. Most other schools have already given out their interview invites for the cycle, so if you haven't heard from them yet, and they haven't explicitly said that they'll look at your March MCAT score, your chances of getting an invite at this point are pretty slim.
If you want CMS to look at your new score, be sure to email them and let them know it's coming, and call them the day you get it, to make sure they're aware. I'm not sure if you can get them to wait for it before ruling on your app, but good luck trying.