Will there be a Sig Pro available with a Picatinny 1913 Rail?
Yes. It is called the Sig-Sauer SP 2022. It became available in the US in 2005. Although was originally chambered for 9mm, its specifications file (PDF), which includes many details and photos, indicates that it will be available in .40 Auto and .357 Sig. We now know it is available in all three calibers, like the Sig-Sauer P226, P229, and P239. The most obvious difference between the SP 2009/2340 and the SP 2022 is the Picatinny rail found on the latter. Also, its trigger guard is hooked, not rounded. Here is a French-language brochure (PDF) that includes some additional photos.
