Reading this article: "The Festo sensor/actuator level now features one of the fastest and most reliable short-range wireless communications systems available. WISA-COM, the wireless communications standard from ABB, will in future facilitate wear-free signal transmission to I/O modules. This will increase machine availability and reduce engineering and assembly costs."
I was involved with motion networks a few years ago (going from ±10V to 100BaseT) and although wiring reductions was key - was skeptical of critical IO or motion going wireless. Figured it was a lot of perception as well for machine troubleshooting and electrical interference was huge concern.
Now- wonder how tangible and how fast the uptake will be...