A top Republican leadership source in the Massachusetts State Senate informs me that there is considerable concern that the National Popular Vote proposal could pass the State Senate. This anti-Electoral College measure would open up the possibility of making Massachusetts award its electoral votes to whatever candidate wins the national popular vote. The measure has already passed the Massachusetts House. If the measure passes the Senate, it would still need to go to the desk of Governor Deval Patrick, who has offered tentative words of support for the proposal in the past.
This source also reminds me, though, that this anti-Electoral College proposal has passed both branches of the Massachusetts legislature in previous sessions and still not made it to the governor's desk. Here's a good narrative of the debate about the Electoral College in Massachusetts over the past few years.
The legislative session ends on July 31. Defenders of the Electoral College would be wise to contact their state senators now. My source indicates that the bill is on the calendar to debate tomorrow, though Senate debate on this measure has been pushed back numerous times. There are both Republican and Democratic defenders of the Electoral College in Massachusetts. This is not a done deal in the Commonwealth, but supporters of the Electoral College will need to fight hard.