Since the Wii U was announced officially at E3 there has been a lot of speculation on all of the details. Price, release date, games at launch versus launch window, and a number of other details to decide whether people want to lay down their money or not. Recently we have gotten a number of sources such as Amazon, Target and other retailers putting up images for the games that are launching with the console. Below are the pictures of the game cases of these various titles as well as an alternative view of the case.
From what we can see, Nintendo appears to have adopted a blue case that will pop out to consumers on the shelf. I think this is good since earlier designs pointed to have the same case as the Wii but just adding in the "U". No word on dimensions but I think we could expect something similar to Wii cases, maybe slimmer judging by the pictures. Until Nintendo shows the game cases themselves I would take each new rumor with a grain of salt, but since these images were from multiple different retailers it gives this rumor good standing.