Well, release date is more or less NCSoft's decision as the publisher and company owner, and they're not known to be patient people when it comes to MMO releases, most of their games (Aion, Tabula Rasa, TERA, GW2, etc ) were rushed like hell and lacked proper endgame content / gameplay balance / engine optimization.
I think today "When it's ready" is merely a myth, a lie, a deceptive idea from another century, used by short-sighted PR spindoctors busy keeping the hype high while comforting potential customers on the game's readiness comes release. Nowadays, most games get released when you can make the most buck out of it. At some point you can't justify anymore extra months of beta / development to shareholders / investors while maintaining a high payroll (where most of the money goes) without any income. Therefore, there are solid chances that Wildstar will be released when NCSoft wants to, rather than "when it's ready".