According to this thread (http://www.teamliquid.net/blogs/viewblog.php?id=60574), Testie was initially invited to join the CJ Entus proteam at Blizzcon, where he initially refused. After being offered another invitation, he immediately jumped onto the deal.
The quote from the blog for those lazy
Nick had received an invite to team CJ in korea after blizzcon and had kind of put that off. But after being REINVITED at WCG he accepted. Testie is 90% going to korea and signing a contract with team CJ. For me, this is a dream come true. I have always wanted to see a fully motivated/trained testie in action and I finally get to see it! Additionally, after meeting Testie I am in love with the guy. Really a nice guy, has dignity and is a classy/funny man. The good parts of him that come through online are truly who he is, minus the ego and blind logic he sometimes bolsters online. He will come here and say "ITS NOT FOR SURE!" or something but just know, this is the closest Testie has been to going and actually doing it, I think it will happen And when it does, all of us need to support and cheer him on. We as foreigners are running out of legit candidates for a non korean pro, lets make it the best we can with what we have!