Duane Liptak, Jr., the Director of Product Management & Marketing at MagPul Industies, responded to a thread on M4Carbine telegraphing the companies intent on “Arm Braces”. Direct Quote below:

More braces and more opinion requests might just hasten an end to this whole market through an opinion reversal, which isn’t good for anyone, so we’ll likely steer clear of any products in this vein. I would prefer to see the ATF realize that this whole SBR thing is silly, as pointed out by the arm brace opinion, so that short barrels are no longer a determinant of NFA status. With all the more strict gun control in many, less free nations around the world, I’m not aware of anyone else that sees barrel length as something that needs to be controlled. It’s silly.

In short, do not expect to see a MagPul arm brace for some time until the ATF has let the clamor surrounding them to quiet down.

Personally, I agree with the approach.