ICANN just delegated the gTLD .WIKI yesterday. It's being managed by Top Level Design, LLC. I'm not entirely sure what that means for all of us exactly, but I suspect that the WMF is going to want to at least register Wikipedia.wiki and Wikimedia.wiki once the gTLD is open for registration.
Some of the new gTLDs are already opening up for registration. .sexy and .tattoo will be opening for registration on 25 February.
It looks like if we want to get .wiki domains we will be getting them sometime in May or June during the "sunrise" period.[1]
ICANN also has a full list of new gTLDs that they have approved.[2]
Thank you, Derric Atzrott Computer Specialist Alizee Pathology
[1]: http://www.namejet.com/Pages/newtlds/tld/WIKI [2]: http://newgtlds.icann.org/en/program-status/delegated-strings