I have this posted in the computer forum but we don't get many hits so I figured I'd share with my fellow Warlocks. If you have already seen/read about this method cool if not here it is.
Copied from another thread :
To play Cataclysm the moment it goes live on midnight Dec. 7 without pre-ordering via battle.net, just follow these easy steps:
1) Make sure World of Warcraft and/or the launcher and background downloader are completely closed.
2) Open up your World of Warcraft folder.
3) Open Launcher.wtf in Notepad and change the "accountType" line from LK to CT.
4)Open Config.wtf in Notepad and change the "accountType" line from LK to CT.
Now load up the launcher and you should begin downloading 700 megs or so of new material. That's the last bit of data you need to play on launch night. Enjoy!
And heres a blue okaying it: http://forums.worldofwarcraft.com/th...=1&pageNo=1#15
Basically you download 7 megs worth of data you would have to load on release night. With this method you just enter your cd key on release night and you're good.