The cartridge form factor here is smaller than anything I have seen from the VME and CompactPCI folks that fits into a muscular server-targeted chassis.
The VMEs of the world might sharpen their pencils over this one. Maybe they could break into the mainstream server world with another chassis.
I believe HP has done something denser than VME (45 processor boards in a 4U) but probably without its mil/aero ruggedness (and cost) and more aligned with PC server standards such as PCI Express and Ethernet interconnects
I'm not really getting the appeal here. 45 wimply processors in 4U doesn't sound that great, given that anyone can get 16 conventional sockets in the same space - 512 cores, 64 ddr3/1600 channels!
maybe the story here is the backplane, which hasn't seemed to get much coverage. does it provide something other than 2x Gb and power?