Honestly, I don't see it happening. MS would be the most likely to fork over the cash in these situations but I'd be surprised if they would in this case. They paid for exclusivity for Shenmue II in North America and that killed sales for the game. I guess if MS could get a worldwide exclusive it's possible. The 360 needs all the help it can get in Japan but I just don't see it happening. Especially if Yu Suzuki isn't involved in the project.
Sony has shifted it's focus to first and second party exclusives. Given their financial situation and their new philosophy, paying for Shenmue 3 exclusive just doesn't seem in the cards. I don't see Sony parting with significant cash for an exclusive unless it's guaranteed to move significant amounts fo PS3 hardware. As much as I'd love a Shenmue 3, I don't think that would be the case.
Nintendo certainly has the cash to buy a Shenmue 3 exclusive and it's large userbase could be appealing to Sega. Sega games have sold best on Nintendo consoles since they've went third party. However, I don't see Nintendo doing this though. Nintendo is the least likely of the Big 3 to purchase an exclusive. I could see Sega releasing a Shenmue 1 and 2 compilation on Wii since it would be the cheapest console to release one for. They could probably get away with a straight port of the DC titles with 16:9 support added. Most DC games already supported 480p so it could be cheap option for Sega. It could be another one of those infamous third party "tests." Outside of that, I don't think we'd see Shenmue on the Wii.
So to summarize, I don't think it's going to happen. I'd love to see Shenmue 3 but I think Sega is just trying placate Shenmue fans via press release. Shenmue 3 was supposedly all but done, if they wanted to release the game, we'd have seen it by now.