Working in a totally different field (healthcare)...I can say while what med. school you come from is important, your resume (i.e. clinical rotations, work experience, fellowships, etc) carries a lot of weight...
Some of the best overall critical thinking doc's (I've known) came from no name schools but did rotations in large inner-city trauma centers...a place most Ivy leaguers steer clear of...in today's age of shrinking general family practice offices and the increasing threat of terrorism with large scale casualties, these hands-on doc's are highly sought after...
I have no experience in your field so these factors might or might not apply.