With regards to the wi.ki domain, I asked people at the WMF back in 2009 about whether they were interested in buying it given that the owner at the time had a notice on the site saying he was willing to sell. The response came back that they were concerned it could be problematic since neither the Wikimedia community nor the WMF has a monopoly on the word "wiki" and the WMF didn't want to overstep their claim to the concept.
As a business decision it might be interesting for Wikia to purchase and use for their own sites, but that's not for us to determine.
Hope that helps, -Liam
wittylama.com/blog Peace, love & metadata