I wish a resource like you're describing would exist. It's a pita finding fixes for certain games on the web (sites disappearing, weird wording in forum posts making searches impossible, etc.). I have a collection of bookmarks on the subject of running old Windows games, but i'm sure this is only a tiny fraction of the info that's available on the web. I'm sure there's lots and lots of info "hidden" inside VOGONS posts, too.
To be frank, i'm not a huge fan of Wikis. The "everyone can edit"-aspect is completely nullified by the fact that not many people actually care to spend time in order to share information. I'd rather start a database with info and use it as a basis for a dedicated website.
jamyskis, if you're interested in creating such a database (or discussing other solutions) and willing to actually invest time, PM me. I'm german, too, so it'll be easy to discuss the matter (; .
EDIT: if one would really go wild on the matter it'd be easily possible to combine DosFreak's Excel stuff with other info to create the basic data. DosFreak, we had a short conversation about databases in another thread, remember? I'm pretty sure you could switch your data "backend" to a db and still edit it with Access or maybe even Excel (not sure about Excel, i'd have to check that one out).