It has been confirmed that the PS4 will be region-free.
The confirmation came from the Twitter of Shuhei Yoshida, President of Sony Worldwide Studios.
And yes, PS4 is region free 😀
— Shuhei Yoshida (@yosp) June 11, 2013
This means that any game can be purchased either domestic or internationally, and it will play on your console, a contrast to Microsoft’s decision to region-lock the Xbox One.