Yeah, i agree. Any hope of a Shenmue III would have to start with the first two releasing on Xbox Games for Demand and PSN (running in HD if possible).
I don't see Shenmue as "feeling Playstation", it has never been in a PS platform anyway. The 2nd one even released on Xbox!
With Yakuza doing so well, I don't see Sony "opening their wallet". I do see Microsoft investing in it, if their japan team is really serious about "saving Xbox" they would do it, it's now the #1 game everyone is dying to see Sega do (Sonic 4 used to be first, but they are doing that now).