Hi. I love bukkit, and I just got a dev (unstable, I guess.) download. So, I have a 1.0.1 server, and I wanna to convert it to Bukkit, with my world, ops, and config. So, how?
just to get the server running in "Vanilla" mode, run the craftbukkit.jar instead of minecraft_server.jar. You also might want to check this BukkitWiki page
the structures (directories, files, names, etc) are all the same. Just copy everything over to your new location (you can even leave the old minecraft_server.jar file there, if you want-- it won't hurt anything) and then run bukkit's jar file instead of Mojang's.
The only problem with pasting a vanilla world into a bukkit server is that it'll generate a new nether and end ( I think )