I'm with 7S on this one. Microsoft decided to implement these features in the One to broaden its appeal, and to take Kinect as far as they could with their current technology.
Since E3 is the big gamer's expo, I think MS knew they couldn't focus on the "casual" aspects of the One in their E3 presentation. So they decided to hold a keynote, as close to E3 as they could and still getting everyone's attention (and having time to refine their E3 presentation after hearing people's reactions to the keynote). Now gamers are pissed that they weren't the center of attention at the keynote, but I think if MS dropped the keynote and squished all the TV and Kinect stuff into the E3 presentation gamers would be even more pissed, because that would leave little time and focus for what E3 is all about: gaming. Never in the keynote did they say games was no longer the focus, or say that gaming was less of a focus with the new console. They just plain didn't mention games. That is, they mentioned NFL and CoD. If you think about it, who would be excited for games from EA sports and a new CoD? Casual gamers. I think many casual gamers got very terribly excited by this keynote. Forza I think was just to confirm it off the bat, so everyone would know that One would launch with a new Forza.
I could be wrong, and MS could spend all their time on E3 focusing even more on TV and apps and whatnot. But I highly doubt it, especially after the reaction the keynote got. If they do though, I'm getting a PS4. So far I'm still leaning towards the One.
tl;dr: the keynote was for the casual market. E3 will be for the gamers.