B&H has the Sigma 24mm f/1.4 DG HSM Art Lens available for preorder. The price is quite reasonable, too – it's less than both the 50mm and 35mm Art lenses!
And while we're on the subject of price, try comparing the Sigma 24mm f/1.4 DG HSM Art to the Canon EF 24mm f/1.4L II USM. I'm still a little stunned.
My preorder has been submitted. [Sean]