Image is a mock-up based on an unofficial sketch of the device. Not the final product.
It's not E3 if there isn't some sort of massive information leak before the event, and this year appears to be no different. Kotaku spotted a sketch by a Chinese blogger who claims to have a 3DS development kit, and the design seems to fit with the Gawker blog has been hearing from other sources.
The design seems to follow the basic layout of the current Nintendo DS, with the notable difference being a much larger top screen which would presumably feature the 3D effect that Nintendo has promised.
Kotaku goes on to speculate that the 3DS will use Sharp's newly-announced 3D camera, which looks a heck of a lot like the small rectangle hovering above the d-pad. They also mention that industry sources are claiming the 3DS may have as much power as a Wii...a few steps down from the rumors earlier this week speculating on the handheld's power.
Much to Nintendo's relief, this leak isn't on the level of the iPhone 4 or even the PSPgo, but it does raise some potential likelihoods for the mysterious device. Thankfully we won't have to wait long to confirm this information. Nintendo will be debuting the 3DS at its press conference during E3 next Tuesday.