It's not much of a secret, at least around folks I've talked with in Seattle.

Here are the the first couple of links that showed up in my google search: http://www.eurogamer.net/articles/2014-01-17-valve-has-no-vr... http://www.reddit.com/r/oculus/comments/2ewj4a/oculus_and_va...

FWIW I have had a demo Valve's R&D headset and it is amazing!