I predict a soft Spring 2015 launch. It could be as early as Winter 2014, but I doubt they'll have it together enough and they don't want to step on their normal Holiday 2014 sales advertising other than to mention that VR is coming.
It doesn't make too much sense to wait longer than Spring 2015. The PS4 that the goggles are attached to is a fixed quantity. Because of this I doubt that it would try to target higher than a 1080p output even if newer goggles could support it. So by Spring 2014 the basic capabilities of the goggles should be known. The only reason to delay at that point would be to wait for better hardware and lower prices. However, that ceases to be an issue if Sony treats this like a soft launch for early adopters. It'd be like what Google is doing with Google Glass. Sony could introduce updated VR goggles in the future, if needed, just like they could introduce a new controller design. Nothing would stop the old goggles from working as-is with games along with the new.
Sony should open this up to independent developers, and I'd expect that by Spring 2015 we'd have a good batch of smaller games to show off on the device. Think of all the best VR demos you've seen to date as a starting point for what to expect. AAA games should have a smaller VR mode that wold let you play a portion of the game in VR. As an example, imaging a game supporting a Horde VR mode.
If at all possible Sony should add the capability to the PS4 to display a non-VR image to the goggles. This would allow the Goggles to be used as a replacement for a TV for non-VR games.