I think Yakuza on the PS3 proves there are plenty of fans (especially in Japan) who would welcome Shenumue3 with open arms. In Japan alone, it would be worth while for Sega and Sony to release Shenmue 3.
i don't think it should be on the Wii at all. Shenmue like i previosuly stated was an amazing genre defining game. Its visuals were amazing, even 5-6 years into the last generation. Sega cannot take a step back on its visual and audio quality. We must also understand that the previous 2 games came on 3 cd's and the Wii doesnt take dvds.
To make a true next gen Shenmue3 which lives up to its predessors, Sega need to make it without jeopardising any of its content and quality. The best place for this is the PS3. You have BR, 7.1 surround, gamers who already enjoy games such as Shenmue (Yakuza and heavy Rain) and do not mind purchasing games which are not your usual generic games.