I don't know if this has been posted, but the new FrontRow can play VIDEO_TS folders.
Just place them in the Movies folder and FrontRow will treat them as a DVD, menu's and all.
Be sure to select Movies > Movies Folder to access them.
Nope, new in 10.5, and I'm totally psyched about it. You can make shortcuts to the video TS folders on a Mac mini (put the shortcut in the movie folder), and turn on file sharing on a different computer that has a large amount of video content. Streaming Video_TS this way works flawlessly over 802.11g.