I see Wikipedia as a microcosm for the internet as a whole: it's great for looking up quick and dirty facts (what is the capital of Peru/will it rain tomorrow/who starred in The Big Lebowski), but I wouldn't use it to solve world hunger. I use it every day since it's probably the best source of pop culture knowledge around.
HOWEVER, what scares me about Wikipedia is that there are dozens of other websites out there that just copy and paste information from it assuming it's fact, and some of those times when Wikipedia is wrong, it's copied on dozens of other websites and gets pushed up to the top of Google search rankings as a result. I've seen this happen a few times now, and it's worrisome.