Duplicating all keystrokes is possible, but like they said, if you get just a single degree off in the direction your characters are pointing, everything falls apart in short order. You would almost need a program to be built into wow to handle it, something like the formation AI from certain RTS games where you can move all your troops at once in a wedge, V, or other formation. Which would be awesome...

In my limited understanding of the mechanics, you would need to do some hardcore coding, and the info you would have to pull from WoW might be violating the user agreement.