In my view it's a block that mixes the exterior design of the Storm with the interior design of this Nexxos XT prototype block, announced some time back,(
http://www.nokytech.net/actualites/4852.html ) but to my understanding didn't came out to market with this name (Nexxos XT), because in the meantime Aquacomputer launched it's Cuplex
XT,taking advantage of some delays.
As you can see the Nexxos XT is a more pinned version of the other variants (HP/XP).