This is actually bigger news than you think: Sigma has announced an 18-35mm f/1.8 lens—but it’s the world’s first ever lens to offer a fixed f/1.8 aperture throughout its zoom range. This literally meaning that it will hold on to light like nothing ever made before. It will suck the light out of the room (try and fathom that). That’s the severity of its capabilities. Currently, its design supports DSLRs with APS-C sized sensors, while achieving the maximum aperture of f/1.8 throughout its zoom range; the previous widest aperture was f/2.8, which isn’t much in comparison now. Internal focusing,lens flare reduction, and minimal focusing distance of 28cm rounds off its other features.
There isn’t much info on availability and price, but no doubt it will be on the pricey spectrum (probably $2k and up).