No, it’s not a Wikipedia spinoff. I have looked around a bit and although it is in the beginning stage I can see this to become one of the greatest resources for SharePoint.
Go check it out! Registration is very easy (if you have a Windows Live ID, that is).
The about us page states the following about the site:
SharePointPedia.com is a web site where people discover and share useful content about SharePoint and SharePoint related products and technologies. It’s a social computing application built on top of Microsoft Office SharePoint Server (MOSS) 2007. Anyone with a Windows Live ID may become a registered user and can then submit content recommendations or requests, leave comments, or just vouch for whatever they like.
Note that SharePointPedia is not a wiki. It’s a “pedia” in the sense of being a compendium of useful content, but rather than being limited by just wiki functionality, it leverages the much broader set of capabilities in SharePoint. SharePointPedia is also about community, where you can find and connect with others, who have similar interests as you or who have recommended content relevant to you. We hope that you will find SharePointPedia useful, and we would greatly appreciate your feedback to make it even better.
The Microsoft SharePointPedia Team