I just ordered a refurbished Canon 35mm f/1.4 L. It arrives tomorrow. So I figured I would torture myself and read up on this new Sigma lens.
If the Sigma is tack sharp at f/1.4, and with 9-blade bokeh... sheeeyiiiit. Now, I'm sure if I would sacrifice robust AF performance, but I'll give Sigma the benefit of the doubt (I mean, my 85L has crap AF, and I still love it). Thankfully, the resale value on my Canon will be high enough that I won't lose much if I go for the Sigma.
I gotta say, though... it feels weird to be considering a Sigma lens that competes directly with a Canon lens.