It won't change anything. The real issue is that as many as 20 students are fighting for each seat at an elite university. No matter how you change the admissions criteria, people will come up with ways to game the system. The packaging has been and will still be exactly what the AOs look for.
Putting more focus on intangible criteria (essay, letters, volunteering work the nature and quality of which are hard to assess beyond what the students describe), instead of the tangibles (courses taken, test scores, etc), only means that colleges will have a much easier time defending their admissions decisions.
In terms of wellroundedness, I also agree with Thomas Percy. I think plenty of people have said that this is just a way to see which middle-class families have the means to help their kids jump through all hoops (the rich kids don't need to jump, they just walk right around the hoops).
