It is true that Adire has liscenced the XBL^2 technology to Destijl Engineering (formerly FRC). Of course I presume Adire has some input as to who gets to use the technology if they don't believe some avenue follows in the proper spirit. As for the performance, it sounds like farnamT is talking about the equivalent of the home theater driver that has been discussed by Adire on this forum, where I believe they are looking at Xmax into the 32-36mm range.
Beware of how you plan to support this product, as I hope it wouldn't be just riding the coat-tails of Adire. It's easy for someone to say "hey, I'd be willing to set up a website and sell the same thing with less profit than those guys." The only thing you have going on your side would be those who will do anything to save a few bucks, even passing over those who have been there to help them all along. I guaranty that support for offering such drivers will require more than just taking the orders. Of course if you feel you can support your operation with the minimal profit I am guessing you have figured in, good luck.
relax guys - adire would still be making money off these drivers as they'd get royalties via the XBL2 license. i don't think dan would license his technology in a way that would be detremental to adire.
with that said, the support definitely still needs to be there if this guy is going to have success around here...