343 did a live stream on Twitch TV this afternoon. David Ellis and Major Nelson give you some news and commentary, while the staff play 5 games (if I remember right). These games include, Infinity Slayer, Regicide, CTF, King of the Hill, and a game mode we have not seen yet called Extraction. They play on Haven, Adrift, Complex, Ragnarok, and Solace
If you missed the stream, you can watch a replay of it here. Scroll down, and click on the videos tab, and there it is. If you are just interested in the game play, it starts at the 12:30 mark.