After the development announcement of Sigma 16mm f/1.4 DC DN lens, Sigma also released a new lens roadmap for Sony E-mount mirrorless cameras, the next lens for Sigma will be Sigma 50mm f/1.4 DC DN lens, it is likely to be announced in 2018. This is a good news for Sony E-mount cameras.
According to Sigma, this mid-telephoto prime lens is already in develop, will be coming in 2018.