Developers Steven Troughton-Smith with TheMudKip working to bring the iOS application functionality to the Apple TV.
"In order to accomplish the task of running iOS applications on Apple TV, the software that powers the app launcher, the iOS Springboard, had to be rewritten. Rewriting the springboard also allowed for another neat, new feature: Side-by-side apps. This concept was demonstrated as early as WWDC 2011 on an iPad, but is much more powerful and important on a device like an Apple TV," (via 9to5mac).
The video below, shows @TheMudkip's MobileX window manager for iOS, and @chpwn's MobileLaunchpad launcher to go with it, running multiple iOS apps natively on AppleTV, without AirPlay.
Here is the video: