Before we start, note that the Wii U hasn't gone into production. Nintendo can (hopefully) fix any Wii U Controller issues before the new console launches, and it's better to bitch about this shit now than after the fact.
Japanese netizens are pointing out that the Wii U Controller's screen appears to have a yellow tint, or more colorfully, that it's "pee" coloured. Some commenters recall that apparently the DS Lite had a urine-colored touch screen when it launched, leading to concerns that the Wii U will, too.
The first above image reads: 色に注意 or "Notice the color". The television screen and Wii U Controller screen are circled. Do that: notice the colour.
Other commenters says that the photographer's camera is to blame or it's the flash or that it's merely the viewing angle.
Out of fairness, I went through the photos that Getty's Kevork Djansezian at E3 and included them in a gallery, along with photos taken by Japanese site Game Watch Impress.
The yellow hue does appear to depend on the viewing angle—sometimes, it's white, sometimes it's yellow. Since I haven't seen it with my naked eye, I'm willing to pass judgment. Moreover, I'll give Nintendo the benefit of the doubt. The Wii U Controller isn't in production yet, so if there is an issue, Nintendo can address it before the machine launches. If the Wii U is truly an HD console, then Nintendo shouldn't skimp on the controller's screen.
【尿液晶】『Wii U』のコントーローラーの液晶画面が黄色すぎる件 [オレ的ゲーム情報]