Just to rest your minds at ease, this plugin doesnt read anything mysterious from the games memory. It uses a FindFirstChangeNotification specified in the Win32 API running in a backgroud thread, otherwise known as a 'File Watcher'. The kernel puts the background thread to sleep while it is waiting for a change to occur.

If you have a look in your WTF/Config.wtf file you will see RealmName = "<name>" on one of the lines. Whenever you switch realms, Blizzard writes to this file immediately, and my FileWatcher detects the change in the config file, and reads the updated information by opening up the config file in the usual manner. It then uses that information to change the MSN nickname.

It does a similar thing for detecting when you go online, by watching the Logs/connection.log. This file is flushed everytime you log into a realm. So when its filesize is 0 bytes, i know that the World of Warcraft has just connected to a new realm. It gets flushed again when you go offline, and the filesize is > 0 bytes then :)