Doesn't look to be larger than normal. You can tell by the mounting holes. IDK why the article calls it an EATX as those are 12" wide by 13" deep. That looks to be the standard 12 x 10 deep - though some ATX mobos have been made shorter than normal recently, so it depends on your frame of reference... OOOPS, now that I do more comparing, it looks WIDER than normal by a couple of inches, maybe 15" instead of 12". Almost no case I know of could tolerate that due to the PCI card spacing, so I'm guessing they'll be bundling it with a custom case as they make those too. Due to this discovery, the following can and should be ignored.
The Rosewill R5600 series I've been recommending forever would hold it and the 4 vid cards, no problem. As will the C-M 690 and 631 I have here - maybe even the old Wave Master. Many cases should as the vid cards aren't even as long as the mobo is deep - IOW, less than 10" long.
Foxconn isn't a big enough force in the PC market yet to make something that won't fit in existing cases. The card slots are arranged differently, but not so much that the cards don't line up with the standard spacing.
.bh.