IUSM has already changed requirements for the class matriculating fall of 2015, so they aren't even waiting for the new MCAT. If you read the stuff out on the MCAT there are a lot of changes. Even current sections are changing to de-emphasize biochemistry over organic chemistry, focus physics to more on living systems as well as the psych and soc material.
We will all know more next year when they release sample tests, but many people that took the MCAT this year thought the test sections for the new test were difficult. At least we will all be in the same boat in the beginning.