Sigma is designing a new f/1.2 lens series UPDATE: for MFT and not APS-C mirrorless
Sigma filed a brand new patent which describes a new range of f/1.2 fast prime lenses. This includes 35mm 24mm and 14mm lenses. This is the official Sigma description google translated from the japanese text:
A large diameter ratio lens may use depiction using the shallowness of depth of field as the expression technique in it. Although many interchangeable lenses with a larger F value than F1.4 are provided, in order that they may make depth of field still shallower, an interchangeable lens whose F value is smaller than F1.2 is desired.
Here are the details:
UPDATE: We just learned that while these lenses are indeed for mirrorless system cameras their angle of view suggest they may be compatible with Micro Four Thirds cameras only (and not for APS-C or FF).