In previous E3 conferences, Microsoft announced partnerships with Netflix, Last.fm, Facebook and Twitter as non-gaming enhancements to the Xbox Live "experience." This year, Xbox Live users can expect 3500 events live and on demand from ESPN in an "exclusive partnership." Content mentioned included NBA, MLB, college football, college basketball, soccer and Sports Center. However, there was no mention of NFL or NHL.
With Kinect, connected viewers are able to vote on which teams fans think can win. There will be stats and live tickers, and you'll be able to switch between games nearly instantaneously. Impressively, this service will be free for Xbox Live Gold members, undoubtedly making it one most valuable additions to the Live service.