While AMD hasn't given a specific release date for their Ryzen CPUs, a GDC talk description may have given us a big clue as to when Ryzen will be launched. The AMD talk at GDC titled "Optimizing for AMD Ryzen CPU," had a description, since changed, implying that Ryzen will launch sometime before the talk. The description used to read:
Join AMD Game Engineering team members for an introduction to the recently-launched AMD Ryzen CPU followed by advanced optimization topics. Learn about the Zen microarchitecture, power management, and CodeXL profiler. Gain insight into code optimization opportunities using hardware performance-monitoring counters. Examples may include assembly and C/C++.
The description for the AMD GDC talk has been changed to remove, "recently-launched," so there is the question whether or not the original description was a mistake or not. GDC runs from February 27 to March 3, so if the description were correct, the AMD Ryzen CPUs would launch sometime before March 3.
Since August, AMD has stated that Q1 2017 is their intended launch date for the Ryzen architecture. However, at CES AMD made no commitments to launch date, price, or clock speeds. We'll likely know more as we inch closer to GDC.