B&H is offering the Sigma USB dock for preorder for $59 + s/h, due for shipping on May 18. The dock allows you to update your firmware and customize your lens:
- AF fine tuning on steroids: You can adjust front and back focus at different focal lengths and different focusing distances.
- For Sports lenses, in addition to firmware updates and AF fine tuning, you can also adjust: the AF speed, the focus limiter (to narrow the focusing to the relevant range for your photography), and the Optical Stabilization.
The dock is compatible with the new Sigma Global Vision CAS lenses, including the Sigma 35 1.4 and the 18-35 1.8. To use the dock, you'll need the Sigma Optimization Pro software which is free, and will be available when the dock starts shipping.
I ordered one for my Sigma 35 1.4 (and possibly the 18-35 1.8) and will post about it. You can also check out this hands-on review from Photography Daily News.