At Best Buy's Zune HD preview today a certain Matthew Arkin on Qik was able to shoot footage of the "Apps" item that resides within the "Marketplace" section on the device. It's still incredibly unclear what Microsoft's plans are for that functionality -- they've long admitted its existence, but have waffled on the name and have been reticent to show it off in meetings with us. Microsoft so far has only promised to have applications on par with the games currently available for Zune, but there's obviously a lot of implied competition with Apple's App Store that the word "Apps" on a touchscreen device conjures up. On video (embedded after the break) the rep is asked if there's an SDK, and apparently