Heh. Okay...Frostbite, lets not even start on Bowser. Focus on Yoshi and Yoshi's island for now. WHY can't Yoshi's Island and Yoster Isle be two different places? It seems to me that Yoshi's Island is a large, unpopulated (well, it's populated by yoshies and other wildlife) land mass in the far-off Dinosaur Land. Yoster Isle is a smaller tropical island that is closer to the Mushroom Kingdom.
About the name issue, perhaps "Yoshi's Island" it not what it's called at all, perhaps we are misspelling it. It could be "Yoshies Island", meaning "Island of Yoshies." Okay, that's a little farfetched, but what I'm trying to say is that the Mushroom World isn't like the real world in that it is largely unexplored. Remote, uninhabited lands don't have offical names. They call those bunch of islands "Dinosaur Land" because there are a bunch of dinosaurs there. And perhaps they call Yoshies Island, "Yoshi's Island" because *the* famous hero Yoshi, who helped Mario save their Princess, is from there.
-TurtleTek
http://turtletek.botic.com