Azhure,
I can't say what your chances might be at U.S. schools, but perhaps a story about me and a friend of mine might be insightful.
My friend, a white woman in her late 20's had been out of school for 6 years or so working as a CPA. She decided she wanted to go to med school so returned to our state university to complete her med school science prerequisits. She ended up with a GPA virtually identical to yours, and got a 34R on her MCAT.
She was VERY concerned about her lack of any EC's, so she volunteered for a few months reading stories to kids in the hospital one day per week while she was applying to schools. She ended up being accepted to every program she applied to, whitled the list down to Yale, our state school, and Mayo. She chose Mayo as it was only $5000 per year tuition. She's a first year resident now.
I had a GPA similar to yours, teaching exprience at our state university at the undergrad and grad level, and co-authored two papers we published in anatomy and surgical procedure. BUT, I took the MCAT before completing my undergrad sciences and only got a 26. I got interviews, but was told the 26 MCAT wassn't going to cut it. So...after finishing the science prerequisites, I retook the MCAT, scored much higher, and was accepted.
Based upon my experiences, and those of others I've known personally, I think your GPA and MCAT (which are both outstanding!) will have a LOT more impact on yuor chances than EC's. Everyone worries about EC's or thinks that they will help shore up an otherwise weak application. From what I've seen, Ec's are a lot less important than people think, and will not in any way make up for a low GPA or low MCAT. Schools are interested in the numbers. They interpret this as an indication of whether or not you can make it through the program, and perform well on innumerable standardized tests.
Just my experience...