My welcome what? 
Web API to allow inputs from Wii U controller.
http://www.nintendo.com/wiiu/built-in-software/browser-specs/sample/
They say HTML5 is all the new craze especially with Unreal being ported...
Who says that? People who program in Javascript?
Yeah, I hear Ubuntu Gay Goat is going to be all HTML 5. Glad I'm still on Windows 
HTML 5 is a step above Flash, at least in terms of freedoms. That said, people act like it's a fad AKA "in style" and want on the boat just to say that they are. I'm too drunk to look at the OP's link right now, but I find it hard to believe that a Web page would have access to a controller's inputs (unless they simulate keyboard/mouse input only). Regardless, I can't imagine trying to use a controller while sitting at my desktop (when I want to use a controller I also want to sprawl out on the couch with beers in me). Not to mention, the Wii controller(s) suck. 
Well, with the upcoming Gamepad API...
https://dvcs.w3.org/hg/gamepad/raw-file/default/gamepad.html
... and with WebGL, soon we'll be able to program all games we like for the browser without limitations, and about 10% of native speed. 
I always thought it was a shame they didn't at least map the directional controls to standard keyboard input. Not really mindblowing, but these features might be nice for Wii tailored sites/crappy on-line games.
The Wii U internet browser isn't the best platform for a game. It isn't hardware accelerated; Nintendo Web Framework, however, is (yes, they have different back ends).
There's a record shop in the city I live in.
Once I went in there. We were chatting about the Gamecube. I was talking about the G that rolls out as the logo went it boots.
I said "What's the underground interpretation of it". A guy behind the counter said "Greedy bastards.".
Ha.