The Japanese company Yasuhara (the maker of the Nanoha macro lens) is going to release a new lens called Madoka - the first 180 degree circle fisheye lens for mirrorless cameras. Here are the basic specs of the Sony E-mount version:
The first Yasuhara Madoka will be released for Sony E mount this spring. The Micro 4/3 version will follow few months later. The company is planning to release also a special software for the images taken with Madoka lenses. Some sample pictures taken with the 180° lens can be found on their website: