I had a great GPA, but my SAT score wasn't as strong. I just graduated from UM in 09. Definitely get involved in as many things as possible, volunteer, sports, student government, jobs. Numbers are important, but they look at the whole package. The essay can really set you apart, as well. I had fun with my essay. I dont know if it's still the same prompts, but I wrote about a difficult time I overcame. I wrote it in the style of the excitement of a football game: 1st quarter, 2nd quarter etc. I was hoping they hadn't seen that from many girls applying.
Good Luck and Go Blue!!!