The Wii U is gonna have 8 GB internal storage with the ability to increase it by HDDs and SD cards. I think they are doing this to cut the price to be affordable which is not a bad thing. Plus, I am sure HDDs and SD cards are getting cheaper by the minute. Although, the games might be a little too hot for a small HDD to handle X_X
Source:
http://www.nintendoworldreport.com/news/30626
Source:
http://www.nintendoworldreport.com/news/30626