That second, competing ballot initiative for a DoMA amendment to the commonwealth constitution did get filed today, right before the deadline. This is the Mass Family Institute version, as covered on the Boston Globe Website.
Various anti-gay factions, right-wing groups, and their buddies of convenience will have to dicker on which they want to support. The poor, tired legislators meanwhile are seeing declining voter appetite for rescinding rights, particularly when same-sex marriage is smooth and painless. Beyond the emotional distress to the minority anti folk, the only problems have been government-induced ones, such as Governor Mitt Romney refusing to update the birth certificates to align with the new reality.
Assuming the second DoMA passes the legislature twice (hmmm, maybe not), it would not get on the ballot until 2008. That's more time for voters to feel safe and tell the haters to chill.