Random observations:
Slick UI evolution. Halo 3's is the best interface I've run into, this looks to build on it.
Veto options: thank you, Flying Spaghetti Monster. Thank you. My only requests: stop the veto countdown once an option has a majority (or plurality) and just load the match, and don't show the votes until the end.
Digging the concept around The Arena, and the subsequent intelligent selection of social vs. ranked play. The constant monthly refresh of Arena ranks sounds like something to discourage alt accounts; I'm curious what kind of carry-over there is from each monthly round.
The play style preferences are interesting, curious how they'll get used. You know people are going to select the quiet option and then blast speakers with noise.
New map name: Sword Base. The pic kinda reminds me of Colossus.
Credit system officially teased: "104Cr" at the bottom of one screen.
Active Roster and party up features are sick, and working that directly into the UI rather than the guide makes me happy in special places.
Lovely stuff. Is it May yet?