That's pretty inventive. It's kinda like the
Speck cover's rear mounting system, a case I have and dislike enormously (but not just because of the mount).
Only problem is the mount adds some thickness to the case when closed. The plastic mount on the Speck just makes the cover feel cheap, too. The big chunk of plastic doesn't feel like it belongs.
Personally my favorite mounting design is the leather holster style, like in the Tuff-Luvs and a few others. I do like that companies are trying to innovate.