This is supposed to be an iPad 2 case, now for sale in bulk by a Chinese case manufacturer. Surprisingly, the design's top right opening is consistent with the rear-facing camera rumor. But what's that hole on the lower corner? Updated.
That's where the speakers are now, but it seems way to big for them. It has to be something else. Kodawarisan says that it is for the rumored SD camera card slot, but it's way too big for that too. In any case, I'm very curious now.
The $2-$4 cases are only available for bulk sale from a Chinese company, with a minimum 1,000-unit order.
Historically, Chinese manufacturers always get a jumpstart when it comes to make skins and cases for future Apple iOS devices. My guess is that they get the physical specs early from the low level operators at the factories that make Apple goods from unicorn ponies and babies. With a rumored February 2011 and a likely April 2011 launch, the iPad 2 specs are most probably already loaded and ready to go.
Update: Here are more photos and a video: