DC Rainmaker recently posted a very complete review of the new SRAM wireless electronic shifting system. SRAM RED eTAP Wireless Shifting System In Depth Review | DC Rainmaker

I may someday want to convert to electronic shifting and wireless sounds like a simple way to go. His review made it sound excellent so I called SRAM. I would consider keeping my mechanical front shifting Shimano Ultegra 6703 with a DuraAce Triple FD. Front shifting is great as well as the rear shifting. I may never convert but if I did then according to the tech at SRAM I could continue to use my current brake/shift levers and install a new SRAM electronic RD, a SRAM cassette and a SRAM chain along with a blip box and two blip switches. I would have mechanical shifting on the triple and wireless electronic shifting on the rear.

An option that would eliminate reworking the frame for the wired system and keep the close ratio cassette and a triple on the front.