As you probably already know, minecraft was updated today and the server software is for now outdated
i know it sucks..
Sadly there is nothing I can do about it until the Bukkit team releases a new jar file to support the newest version of minecraft.. how long that will take? im not sure. this is all out of my controll
For now if you want to play one the server you will need to downgrade minecraft to beta 1.2.02, how you do this can be learned by googling: downgrade minecraft
The server will be updated as soon as possible