I tested DayZ's sprint and jog speeds and was surprised to find the following:
sprinting = 23.15 km/h (+/- 0.15 m/s)
jogging = 14.7 km/h (+/- 0.03 m/s)
Sprinting speed is the same as in ArmA 2, and jogging is about 18% slower than in ArmA 2.
So the player run speed is not a real issue. The main problem is the unlimited turn speed. Since the devs chose to remove the mechanics limiting players' movement in the first place, they may be averse to reinstating such limitations. I hope they will find a way to prevent all the crazy, spastic movement while managing to retain fluid controls.
For comparison, in ArmA 3, jog and sprint speeds are 14.3 and 24.7 km/h for a civilian, and IIRC about 13.6 and 18.2 km/h for a kitted soldier (depends on gear). And of course, in both ArmAs, you can't sprint indefinitely.