hi am i new to dualboxing also and i use a iMac so here is what i have done so far
downloaded clone keys from http://code.google.com/p/clonekeys/

and to open multiple windows of wow go to applications, World of warcraft folder and right click on world of warcaft program (not the launcher) and select show package contents, go in contents folder then MacOS and there should be a file called world of warcaft. Drag this to your dock in the same part as the trash can just next to it (try not to drop it in the trash lol) and then you should be able to open multiple windows

let me know how you get on and i am now going to give spaces a go