Looks like Sigma has another winner on hand. if only they can keep sample to sample variation down and can price it competitively. this new lens will sell like hot cakes.
http://photorumors.com/2014/04/05/first-sigma-50mm-f1-4-dg-hsm-art-lens-review-it-trounces-any-similar-model-available-for-less-than-4000/
http://photorumors.com/2014/04/05/first-sigma-50mm-f1-4-dg-hsm-art-lens-review-it-trounces-any-similar-model-available-for-less-than-4000/