What a coincidence that someone asks, because just yesterday I updated the old TODO page trying to set some definite goals for the short run.
I don't think that replicating the Arch Wiki is a good idea, I find it a convoluted mass of information that is replicating a good part of the documentation from a ton of software applications. Take the article about VirtualBox for example, which goes to great lengths to explain everything anyone might need to know about the software, no matter if it affects their distro or not or if that documentation is readily available from upstream.
Just a few hours ago (I tell you, your question arrives with excellent timing...) I tried to install VirtualBox on Void and use an old image I created in Mint months ago, only to get the dreared "can't find the kernel module, -1908 yadda yadda" error. I then went to check the article about VB in our wiki and found I wouldn't have had such problem if I just had bothered first to check it out and follow the simple instructions a fellow Void user (developer?) had posted 2 years ago. In fact, he did it in such a smart way that the information still remains valid today. And nobody had to write 50kB of wikitext when 2kB will suffice for most people.
I know I may be oversimplifying things but that's how I see it. In the short run at least, I think we should focus on updating/organizing the documentation available and possibly writing new articles that help shortening the gap wrt more popular distros. How do you replace the login manager? What are the exact requirements of every flavour of Void? Can I install .deb packages anyhow? What if I want to install Apache, or a complete LAMP server? etc...
Those are my two euros at least.