Those 30 pins could handle a whole hell of a lot, including serial, line-in, and component and composite video. With the switch to the new 8-pin Lightning connector on the iPhone 5, new iPod Nano, and new iPod Touch, some notable benefits were achieved, including a full digital pipe, a fully-reversible design, and a much smaller footprint. But some things might have been lost, like video out.
It’s a possibility, as noted by iMore, that we will see video-out support added through a Lightning/USB to HDMI breakout cable in the future, but it is also possible Apple will promote AirPlay and Apple TV only from here on out. As of right now, the iPhone 5’s spec page only lists “AirPlay Mirroring to Apple TV support at 720p” and “AirPlay video streaming to Apple TV (3rd generation) at up to 1080p and Apple TV (2nd generation) at up to 720p” under TV and Video support.