According to this video, Shenmue 3 has been confirmed for PS4.
When asked for a source in the comments, they just said that they have an insider source, and that it's in the magazines in Hong Kong.
Until other news sites start talking about it, I'm just not ready to believe that it's been completely confirmed. I do think it's possible they're talking about making as a PS4 exclusive though.
http://www.youtube.com/watch?v=J_K_e3dB ... e=youtu.be