So I actually did not see this until after I published the Razer story. Just a few hours ago, Corsair posted an announcement to their Facebook page that claimed a "cbange" in launch date for their Cherry MX RGB-based keyboards. I actually forgot that the K70 RGB Red was supposed to be out already, with availability listed as "late July" (the rest were scheduled to arrive in "late August"). Corsair does not yet have a new date, but will comment "in a few weeks".
Got to say, that does look nice.
While, again, no further details are given, it sounds like a technical hurdle is holding back the launch. Corsair claims that they want the product to live up to expectations. This, of course, chips further at the company's exclusivity window and could put them in direct competition with Razer's custom design, and may even be available second, almost in spite of the exclusivity arrangement.