I am wondering if it is possible to make some sort of a Minecraft server on Arduino, but all simple host the MOTD. Not a server where players can join and play, just so you can ping the Arduino from Minecraft client and display a MOTD.
It could be possible but it requires a lot of work. First you need the Arduino to run Java on the Arduino, then it loads the minecraft_server. There is some stuff on the Web you might try looking for it.