The Wii U's eShop has been a closely guarded secret up until this point, but courtesy of Nintendo's Japanese website we have the first picture of it.

As seen below, it looks quite a bit like the 3DS version of eShop:

Wii U eShop features
• Demos, screenshots and trailers.
• See how players rated a title (star system).
• Check Miiverse comments about a game.
• Make purchases while other software is running.