Well, this is a bit awkward. It seems as if there is no "@" symbol in the password entry section of the Wii U's Netflix app, making it impossible for users with the symbol in their password to sign in to the service. 

A group of frustrated Reddit users first uncovered the issue, and reported that Netflix support technicians were no help in subverting the problem. Currently, the only solution to this issue is to sign in to your Netflix profile online (which, at least, you can do via the Wii U's Internet Browser) and change your password on the official site before returning to the app within the Wii U and signing in with your new password. 

The Wii U's Netflix streaming app is one of the system's major draws for videophiles, along with the Amazon Streaming and Hulu apps. These were included to tide users over until the Nintendo TVii app launched; this ambitious app aims to encompass all video streaming services for the console, which are set to later include HBO and live television streaming, and display them through one convenient hub. 

We'll have more on the Nintendo Wii U very soon, so keep an eye out for the latest coverage. Until then, enjoy your new console and hopefully Nintendo will push a fix for that Netflix issue soon.