Although there is no ETA for the Domino XL machine and larger Domino tendons in the USA, I have made it clear to my favorite local Festool dealer that I will buy the machine with all the necessary bits and a supply of the XL Dominoes themselves.
Perhaps Shane or someone can tell me if the XL will use longer Dominoes than the Domino 500? I see both have 8mm and 10mm, but perhaps the XL Dominoes will be wider and longer.
As it is I hardly ever use 10mm Dominoes, but I have products I want to prototype which would benefit from wider and longer Dominoes. I do own a fairly new floor mounted dedicated mortising machine which can use 25mm set up. I would not think of trying mortises thicker than 14mm hand held, but I have faith in Festool and a jug of green Kool Aide.