yup that what works
yes you can play in windowed mode you just can't toggle between windowed and non- windowed. I too didn't think you could on a mac but read you could. I don't play that way but I think you can hold down the apple key while the game is booting to have it be in windowed mode. I tried it and yep, yep sure enough you can. I am playing right now and online at the same time.