Considering that BD-50R disks (when you can find them) in Canada are priced at about $14.00 each, that would put the cost of a XL disk at probably $35.00 each. Add to this that the XL disks can only be played on a handful of drives.
Plus the fact that the Recording Moguls are going to do their utmost to prevent this media from being available at any price in North America.
Not bloody likely.
For the price of 4 XL disks, I can get a 500 gig portable hard drive AND a decent media player. Won't take 3-4 hours to burn a disk and the hard drive is easily erasable and reuseable, and I've saved myself the cost of the BDXL drive in the first place.