At http://beagleboard.org/boards, the product comparison table lists three of the entries for the X15 as “TBD”, but since the board is shipping, I assume that’s not really the case. I don’t know who to contact about this or how, but it seems like it should be updated.
Also, the board images appear to be out of date (at least with respect to solder mask and silkscreen details in images provided by Mouser or Digi-Key). Less pressing an issue, but it doesn’t inspire confidence when you go to a distributor page and it appears to picture a distinct product/version.