Via it's own website, Nintendo has put out the specs for the Wii U Internet Browser. Here are those specs for those who care about that sort of thing.
http://www.nintendo.com/wiiu/features/browser-specs/
So yeah no flash, which was to be expected and I think was already confirmed...
http://www.nintendo.com/wiiu/features/browser-specs/
Browser Engine
NetFront® Browser NX v2.1
User agent
Mozilla/5.0 (Nintendo WiiU) AppleWebKit/534.52 (KHTML, like Gecko) NX/{Version No} NintendoBrowser/{Version No}.US
Supported Protocols
HTTP1.0/HTTP1.1/SSL3.0/TLS1.0/TLS1.1/TLS1.2
Web Standard
HTML4.01/HTML5/XHTML1.1/CSS1/CSS2.1/CSS3. (partial functionality)
DOM1-3/ECMAScript
XMLHttpRequest/canvas/Video/Web Storage (partial functionality)
Web Messaging/Server-Sent Events/Device Orientation/WOFF/SVG
Plug-ins
Does not support plug-ins, such as Adobe Flash.
TouchEvent
The browser supports only one of these at a time: touchstart, touchend, touchmove, touchcancel
Screen resolution
If it isn't specified, width is 980px layout
It is possible to specify width/height of the viewport within the HTML’s <head>...</head>, and specify scaling permission via user-scalable meta tags.
(e.g) <meta name="viewport" content="width=device-width, user-scalable=no"/>
Saving/upload of image/video
Not supported
Video Format
MP4, M3U8+TS(HTTPLiveStreaming)
(Some videos may not be playable.)
Video Codec
H.264 - MPEG-4 AVC Video
(Some videos may not be playable.)
Audio Codec
AAC - ISO/IEC 14496-3 MPEG-4 AAC
(Some audio may not be playable.)
So yeah no flash, which was to be expected and I think was already confirmed...