It's unclear if Yoshida's statement indicates the PS4 will be region-free in the same way the PS3 is. The PS3 can play game discs no matter which geographical region they're tied to, minus the sole exception of Persona 4 Arena. There are region-based PlayStation Network restrictions when it comes to downloadable games on the PS3.
Update: When approached about Yoshida's comment, a Sony Computer Entertainment spokesperson gave us the following statement:
"In general, neither digital or disc-based games will be region locked, but we recommend users purchase games at the region of their residence to guarantee the best overall consumer experience (eg, customer service). In addition, certain software makers' game titles may be region locked."