Now that would be sweet. And funny as all hell.
I would pay money to see the look on Watts' and Bloomberg's faces should that come to pass...
I don't know that it would be a huge deal to them.
1. The anti's and MSM have for a LONG time been deliberately confusing the non-gun public that semi-automatic military styled rifles are fully-automatic already. Making a stink now runs the risk of exposing the falsehoods. "
Wait... whut? Thems M4's yous always on da news bitch'n 'bout n the schools gettin shot up, they's aren't automatics?"
2. Because of the confusion, sensationalism, and fear-mongering, the anti and fence-sitting public already thinks full autos are "legal" and "common".
3. Despite the floodgates being opened on NFA due to the shrinking dollar vs. the $200 tax, and the Internet getting people educated on the process, it's still a tiny fraction of the total gun purchases/transfers in America each year. And even with the education and more dealers than ever willing to walk you through the process, the extra $200 the forms, making a trust or CLEO sign-off, and the wait is still a huge barrier to entry to all but the most fervent gun-nuts. Take away the tax, and I bet 90%+ of the "go to Cablea's once a year" type of gun buyer would still never bother.
IMO, those who have willfully tried to mess with the NFA on the Federal level, namely Hughes with (what he thought would be) the poison-pill amendment to the '86 FOPA, and now Obama/Holder with 41p. Which I personally believe was the one quick and easy, or so they thought, way they could claim they did some "gun control by executive order" and keep the press off Obama's back about it.
Either way, the anti-gun activity targeted at the NFA, what little there is, has always kind of been a backhanded swipe at a small consolation prize. I don't think NFA has ever been mainstream enough to make it a major gun control target. We have to step outside our worldview from the Internet gun boards and realize that it's just not on the radar for the majority of pro or anti-RKBA people.