Wikimedia (our umbrella organization) and MediaWiki (our software) now have official logos, namely the second and third place submissions from our contest. I have used the second place design by User:Neolux as the more important Wikimedia logo. I think it looks very nice on the Wikimedia Foundation page, please do take a look:
http://wikimediafoundation.org/
My sunflower logo, which came in third place, seems well suited for the software. The square brackets give it a technical look, which may be inappropriate elsewhere, but is a nice reference here. I've also added a little slogan to the logo. You can see it here:
http://wikipedia.sourceforge.net/
(We may want to move the project to mediawiki.sourceforge.net, but that's not a priority.)
I for one am happy with the logo situation now. I think our projects altogether have a far more professional look than when we started.
All best,
Erik