I agree with having the documentation available inside of a .roswiki file. I like the suggestion about gamification of tutorial contributions/wiki maintenance. But I do not like it enough to implement it myself, so I guess I don't like it that much.
I'd like to add that it's not the quality or decay of tutorials/documentation on the wiki that makes it bad in my perspective, it's the navigation of the website. Finding relative information and "picking your own adventure" to coin MPurvis is the major downside.
There is plenty of useful information available, and after 2.5 years of working with ROS I'm still finding documentation and tutorials that would've been helpful 2 years ago when starting to integrate into the community.
tl;dr improve ability to learn from website, find relevant documentation easier