I have no news, but my prediction is that, if all goes well, CV1 will be released in November 2015 for the holiday shopping season.
Since OVR says that they are planning not to go retail (at least that's the current rumor), it might get released a bit earlier, like October 2015.
From a strategic preparation standpoint (giving us devs time to create content) and hype-cycle standpoint (holiday must-have that gets sold-out is understandable by buyers and only increases future demand), it seems to me that this timeframe is the most likely.
Earlier will cause the Rift to fall into the potential problem area of not enough content, later means a release after the holiday season, and that's a toxic release timeframe for any new tech device. If it's not late 2015, release would be problematic before about March/April 2016.
My guess is the announcement & pre-orders beginning in March @GDC with shipping in June or July . With all the extra financial/human resources available compared to between the release of the two DK's things like R&D should be able to happen a lot quicker than we've seen before but time will tell though .