XCOM: Enemy Unknown Cheats
Thankfully I have solved this issue. I bought Dishonored on Steam and I will be getting X-COM from GameStop. I will install X-COM and while that is installing I will play Dishonored.
You can install and play at the same time. You simply minimize to desktop while playing the one game, and then select resume on the install/download while playing the other. Also, I think Fullmetal's point is that he will have one ready for download, and the other he will have to go pick up so it will not be ready for immediate play. He can play some Dishonored for awhile, and then go pick up XCOM a little later in the day.