Well, the easiest way would be
1. set your display settings of your computer to Dual Screen (don't know where exactly, somewhere in the settings of your videocard ...in windows vista you dont have horizontal span anymore )
2. start each wow in windowed mode (display settings->windowed mode in the options of wow) and then hit the to maximize the windows.

The .bat file is helpful to change the resolution of your wow windows, but if you have 2 monitors and 2 wow windows, the easiest way is to just maximize them on each monitor