Making the next Apple TV a better presentation tool.
1. Wi-Fi Direct.
2. Battery pack for Apple TV. Presumably a device the same size as the Apple TV could supply enough power. Ideally it would be a "sleeve" design so there is only one item to deal with. The internal transformer of the Apple TV complicates things slightly as AC will have to be supplied, necessitating a transformer in the battery back as well. Fortunately the power draw of an Apple TV is very low (on the order of 1 watt plus a bit for the wifi).
All a presenter would need is access to an HDMI cable that is connected to a TV. Pretty standard these days.
eg: Detach HDMI cable from a DVD player in the presentation room. Plug it into the Apple TV. A 1 metre HDMI cable would be worth packing along to give the option of plugging directly onto the TV, but generally accessing the back of a connected device like a DVD player is more convenient than accessing the TV inputs directly. Showtime. Presentation could be Air-played from an iPhone, iPad or Mac. Presently the iPhone 5 has a Wi-Fi Direct capable chipset.
In lieu of a battery, the DVD power cable could likely be used, but ideally hookup would be as quick and non-invasive as possible.
Currently you need:
1. Access to a wifi network or bring one along (eg Airport express).
2. AC power, which can be awkward depending on how the TV is set up. crawling around behind a cabinet for looking for a free outlet before presenting is... suboptimal.
Of course this will require enabling Wi-Fi Direct or an Apple specific protocol in software and compatible chipsets in the Apple TV and connected devices such as the iPad.