Vim tips and files are scattered all over the web. Usually in sites that are brutally difficult to use.
Yet there are TONS of people using VIM.
Solution:
A contrastingly clean central source of all things VIM that's user-maintained through GitHub.
Questions: 1. Would this interest you? 2. What would be the top-level nav links? (A little virtual card sorting here) 3. What would you expect on it?
I think you should consider discussing this on the vim mailing list (maybe you have, maybe others have).
It's a glaring deficiency of the vim ecosystem, I agree. Every single time I use vim.org and the vim wiki, I hear David Cross in my head saying "THERE MUST BE A BETTER WAY". The fact that David Cross is in my head then concerns me for several minutes and I forget about Vim.
I'd love a way to update a wiki via a dvcs. Then it becomes a help file as well. Here's a project I would be more interested in:
Design a next gen Vim help file / wiki system that would allow for local help file access to extend naturally into user contributed wiki content. Integrate scripts into the above. Allow all of it to live in any of several popular DVCS's. Ensure that the scripts that live in it can be independently sourced using Pathogen, etc.
I found this one http://www.digilife.be/quickreferences/QRC/VIM%20Quick%20Ref... but it doesn't have anything about tabs, buffers and splits. A full quick reference in the same style as the one above would be good to stick next to a computer.
Right now I'm keeping http://vim.runpaint.org/toc/ open in a browser tab and referring when needed. It's simple to refer and read.