Just posted! Our new lens review of Sigma's latest baby, the 50mm F1.4 EX DG HSM. This optic brings the classic 50mm focal length bang up to date, incorporating ultrasonic focusing for all camera mounts, and the use of an aspherical element for reduced aberrations. Serving dual purpose as a 'normal' lens on 35mm full-frame and a short 'portrait' telephoto on APS-C, the fast 50mm is a great complement to the now-ubiquitous slow kit zoom, but does the Sigma offer any compelling advantages over the camera manufacturers' own versions, or is it a case of too little, too late?

http://www.dpreview.com/news/0808/08081802sigma50review.asp

Why would someone pay $500 for this lens when they can get the the Nikon or Canon version for $200.00 less? I don't get it.

Did ya go through the review? Think of it as a 1.2 "lite" on the canon end. The AP blades are rounded, less vignetting, and it has hsm with full time manual override. I'd consider the sigma 1.4 instead of the canon 1.2 (obviously after taking home and testing and looking at sharpness etc.).