Some people are using a "multibox program" but I have never tested it and have no intentions of doing so. That apparently is to simulate a keyboard multicaster in software over a tcp/ip network.

As for sending multiple keystrokes to multiple WINDOWS at the same time - I am sure it is possible but I have nothing to give you at this time. There is no *easy* way to do that that I am aware of. I bet it would be much easier to do with Linux though..... perhaps setup two X'es and configure the keyboard to send key presses to both WoW's.....

Pretty sure that you will need a fair amount of Linux know how to pull it off but that is most likely how I would do it if I really wanted to.