On the legality of this, the U.S. determines a firearm as a machine gun when more than one round is fired for one pull of the trigger. The options for this double-barreled pistol as quoted from their website,
"The AF2011-A1 (“Twenty Eleven” for aficionados) can be ordered either with 2 independent triggers and one sear group (left or right, with user-interchangeability for right or left operations) or with 2 triggers permanently joined and the choice of 1 or 2 sear groups."
So, you can get either 2 independent triggers and one sear group, which lists this firearm as a machine gun (for one trigger or the other will act on the sear and fire both barrels) or with 2 triggers permanently joined w/ 1 or 2 sear groups. As the laws govern the pull of trigger as the determining factor as to the fact a firearm is a machine gun or not, option two will make it legal to own. Even with both triggers permanently joined, you may pull on one (left or right) with only one finger but both triggers are pulled because they are linked. The law doesn't state anything about governing a firearm with two triggers, both needing to be acted upon by a users finger(s) or the fact that a firearm with two triggers require a sear system for each trigger.
Atleast that is my understanding of the law.
Who knows, maybe we can buy them before the government puts admendments on the law controlling machine guns that includes rules on the number of sear systems and multiple triggers.
As it is an oddity, I'd purchase one just for the novelty and showpiece. Of course I'd take it to the range and play with it too.