I think there is real potential with that idea and I don't see the the Shenmue Online deal being transferable to this situation in terms of determining its success or not.
Yakuza MMO online would have quite a bit more going for it then Shenmue Online ever did and it would be more fighting orientated.
Just imagine if you could create your own Yakuza character, fight and train on PSP and PS3 and take online and then Sega could host tournaments with real prizes in the underground arena.
Seriously, this is a good fuckin' idea.
Sega, hire me you idiots!
Do you have any idea of how much it would cost to make and upkeep such a project? Look how cursed Huxley has been because of silly ideas like these, especially with console to handheld interaction being something even Blizzard never even attempted, and they are worried they will lose a lot of money with Facebook interactions!
SEGA would never, ever do this. That is a horrific idea, logically speaking.
I don't think it'll be limited to one on one fighting.
Look at how the fights are presented from the camera, it is hovering next to the player in a way that would never work well with multiple enemies to have to worry about.
Also notice that the graphics are a smidge better than Yakuza 2. If this was the same kind of style of gameplay as that it would not be possible on the PSP at all.
Nagoshi himself said the game would have a much different style of play even! The only thing that hurts my theory is that the game will have 4 player support, but at the same time we do not know what that means as they never said "4 player battles" or anything similar. It could be anything!