Yes -- I remember seeing the demo videos for Tech21 and d30. Very impressive stuff. This appears to be a great price. From what I can see, it looks like the long dimension would be about 1/2" longer than the Nexus 10, and the narrow dimension about 1" greater than the narrow dimension of the Nexus 10. The case is definitely a bit oversized. However if it's leather, with two layers of d30, it would be a pretty fantastic case / sleeve for $5...
Edit: I searched some more, and it appears that the same d3o case is being sold on different sites anywhere from $5 to $45. For $5 including shipping, I figured it's worth a risk. If it's leather with d3o that will be a fantastic deal. If it's ballistic nylon with d3o then it's still a good deal. Already shipped. I should have it next week. Really curious!