According to boston.com: "Under the law . . . all 12 of the state's electoral votes would be awarded to the candidate who receives the most votes nationally. . . Once states accounting for a majority of the electoral votes (or 270 of 538) have enacted the laws, the candidate winning the most votes nationally would be assured a majority of Electoral College votes. That would hold true no matter how the other states vote and how their electoral votes are distributed."
Obviously, a Constitutional amendment could never happen, since it would require ratification by 3/4ths of the states -- and the Electoral College benefits the individual voters in the states with smaller populations (which constitute greater than 25% of all states). But this end-around seems Constitutional, at first glance, since states can set their own rules on how they allocate electors. Now if they could only repeal the 17th Amendment, our system of representative democracy might make a little sense.