http://zeissvrone.tumblr.com/
$99 is a nice price point and it's release date is errr... now!
Ok how it works with a phone and what you can actually do with it are a bit of mystery.
Apparently only works with Samsung/Apple phones at the moment as those are the two trays available.
I'd rather wait for the technology to mature. Essentially you're paying 100 euros for a piece of plastic with two lenses.. Kind of expensive..
Maybe save yourself a few quid with this (http://www.banggood.com/Novelty-DIY-Cardboard-Virtual-Reality-VR-Mobile-Phone-3D-Glasses-p-940425.html) instead and let the novelty wear off, not Carl Zeiss lenses though.
http://www.wareable.com/gaming/hands-on-with-google-cardboard this is for you, buy it for the name! :D