Well, a few issues off the top of my head
We've strongly de-emphasized custom domain names, for reasons both technical (it makes unified logins incredibly difficult, and nobody knows these sites are part of a network when they all have different names) and practical (naming is ridiculously difficult, takes forever, and is kind of a distraction.)
The actual domain is a pay-for-service affair, which is.. kind of antithetical to everything we stand for. If we assumed the domain, it'd be like a staunch republican switching districts to a heavily democratic area. There will be confusion, and a lot of it, and perhaps even some brand poisoning by association.
I appreciate the heads up, but it feels like a bad fit... I'd be happy to entertain any evidence to the contrary.
As this site is called WordPress Answers I know that wpanswers.com is not being use. (The site is run on WP>org and the only post is the default admin post!)
So I would say to use that.