The Xbox 360 Dashboard might not want you to know it just yet, but hidden among the 'Game Videos' section of the game marketplace is a just-released 10-minute gameplay demo for BioShock Infinite. The guided demo will go live everywhere else tomorrow, but if you've got an Xbox 360, we'd suggest queuing up the clip for download right now. It'll probably be the best ten minutes (involving telekinesis) you'll experience today!