Lifeproof has been very unresponsive to questions about anticipated release dates. They're constantly inundated with questions about it on their Facebook page and always give the same canned answers - some variation of "We're working on it" or "We'll let you know when they're available".
I've been looking at the Wetsuit cases by
Dog and Bone - they're not available yet either, but their prices are lower than Lifeproof and they look to be good cases. As soon as they release one for the 6+ I'll be buying it - I've pretty much given up on Lifeproof.