For anyone who uses Wikipedia's lax security to add links, let me make a suggestion - add your link in the "discussion" section for the page (example) and ask others to review whether the link you're providing will be pertinent or not. This way, you get a real, non-nofollow, indexable link from Wikipedia and you are at a much lower risk of pissing off the community of editors.

Granted, Wikipedia's fact pages do provide some nice click-through traffic, and the value of being on the actual page, both for visitors and search engines is greater, but I think if you have doubts about the validity of the link, let someone else provide feedback. You may even get some nice insight into what your page may be lacking (or why it's not a suitable resource).