Is anyone modifying / update this wiki?
Yes I wrote nearly the entire Jetson TK1 Wiki and I still update it when I find issues, but I don't work for NVIDIA anymore and I'm not using Jetson TK1 much at the moment, so I don't update it often. I actually used these OpenCV install instructions on Jetson TK1 just a few weeks ago, so it certainly is up-to-date, even for OpenCV 3.0, but of course it might not be perfect, there are a lot of combinations of L4T and OpenCV I haven't tested.
Jetson TK1 doesn't normally come with OpenCV, so this page tries to describe the different options you have for putting OpenCV on your Jetson TK1. And at the bottom it links to the OpenCV Tutorial that shows how to get started actually using OpenCV, after you've installed it on your Jetson TK1.
If you've tried following this Wiki page and are having trouble, the best place to ask is NVIDIA's Jetson TK1 forum at "http://devtalk.nvidia.com/default/board/139/embedded-systems/".