I don't know, when I see Vive pre-orders or orders starting, I'm going to be first in line. Sure, if Oculus announces something earlier that's much better and shipping soon after I'd go with them, but they haven't shown much interest or enthusiasm with their PC based kit lately. I'd rather have a Vive (which looks awesome) at the end of 2015 than to wait for Oculus "forever". They seem like they're using their 2 BILLION for things like the Galaxy Gear VR and not for the serious PC gamer market. Look at what John Carmack is concentrating on within Oculus - mobile. That should tell us something.
There's a lot of time left before the end of 2015. Keep in mind that Crescent Bay was already actual hardware long before HTC-Vive even announced anything....
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I think Oculus is being strategic.
When you're playing Texas Hold'em and you've got a strong hand you keep your mouth shut and your eyes on your cards. You let the kitty rise, and then when its time to show 'em, you clean house.
Realistically, Oculus gains nothing by talking too much right now and they risk informing their competitors on what cards they hold.
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As you're rightly wondering, if Oculus will support PC gaming then they'll make sure to announce before everyone and their mother has had a chance to sign up for Vive.
In fact, I predict that Oculus will time their announcement very closely with the start of Vive pre-orders. (not the developer order that's happening now)
No doubt, Vive looks great, but I'm not signing up for anything until I hear more about Oculus.
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One way or the other, I am EXTREMELY excited about the advent of the age of VR in PC gaming.
I already love my DK2, and I can't wait for either a Vive, or CV Rift, or whatever else shows up before next year.