The ability to download full games will be available at Wii U launch.
http://www.nintendoworldreport.com/news/29983
New Super Mario Bros. 2 won't just be coming to retail stores in August, it will also be coming to the eShop as a download. Additionally, the ability to download full games will be available at the launch of the Wii U. The news came out of Nintendo's end-of-the-year investors' meeting in Japan.
Part of the logic behind this move, according to Nintendo's Satoru Iwata, is that game life is getting shorter, and this offers a place for games to be available past their retail shelf life. Retail stores will also sell download codes, and as such, Iwata doesn't expect a big price disparity between retail and download.
Wii U will be out worldwide by the end of 2012, and according to the same report, price details won't be announced at E3 2012.
New Super Mario Bros. 2, revealed last week, is scheduled for an August release. We reported earlier today that it seemed like Nintendo would be offering full retail releases soon, and it looks like they are.