[quote name='alongx'][quote name='bjschre']Plus PS2 probably couldn't handle a graphic update over the second one either, but I could be wrong.[/quote]
You're wrong. There, I said it.
http://www.gamespot.com/xbox/adventure/shenmue2/review-2.html
[quote name='Shenmue II Review at Gamespot']While Xbox version retains everything seen in the Dreamcast game and tosses in improved lighting, as well as an improved character model for Ryo, the visuals are far less impressive overall.[/quote]
http://xbox.ign.com/articles/375/375803p4.html
[quote name='Shenmue II Review at IGN']Though Microsoft and AM2 made some graphical enhancements, they were still working from a Dreamcast base and that's evident. Side-by-side, the game looks much better than its Dreamcast sibling, but it's still not up to Xbox standards.[/quote][/quote]
Just because the game originally ran on the Dreamcast doesn't mean it could run on a Playstation2. Sure the PS2 has more memory, but it can't match the Dreamcast for texture processing, and this is what really limits Shenmue especially. Shenmue has some pretty large textures, and lots of them, and I'm not certain that it would be able to run on a PS2 at the same quality as the Dreamcast.
I saw an article comparing the PS2 and DC, and the author showed pretty convincingly that, though the PS2 was better for a lot of applications, it was pretty clear that the DC was capable of a lot of things the PS2 couldn't hope to do. I couldn't find the original article, but I think it's been reposted here:
http://forum.pcvsconsole.com/viewthread.php?tid=2807
And here is a direct comparison of the specifications of PS2 and DC :
http://member.telpacific.com.au/trat2422/d-ps.html