Seattle Tech Wiki should probably be on this list of local tech wikis. It mostly targets tech startups, so a lot of entrepreneural focus, including a lot of blank pages in these areas they wanted to have filled in. Still, some useful links on that site.
http://www.seattletechwiki.com/index.php?title=Home
It's sister site, SeattleTechCalender.com, is very popular for event exposure. Wikipedia Seattle should consider getting a recurring event listing their monthly meeting on that site.