Zeiss posted a teaser on their official blog about "new super wide angle lens from Carl Zeiss":
"It is here: the lens at the top of the wish list of our community on Facebook and Flickr. Now you can look forward to exploring entirely new creative opportunities. In the next few days, this is where we will be showing you everything our new SLR lens has to offer."
I am sure this teaser is for the new Distagon T* 2,8/15 ZF.2/ZE super wide angle lens that is expected to be released on March 16th, 2012 and will start shipping in May. Expect the price tag to be around $3000.