It really it a natural evolution of the console. The biggest thing to me is now the Xbox will serve as a cable box too. So no more swapping inputs to go from Xbox to TV. The only thing I didn't hear was whether or not is supported DVR functions. If it does it will be a real game changer.
And as an aside, they announced a live action Halo TV show to be exclusive to Xbox One. Being done by Spielberg no less. I really enjoyed the Forward Unto Dawn web series so this is gonna be awesome.
And then of course the better gaming hardware and graphics and faster/better reactions to voice commands.