Head here to read about what the features are all about:

http://www.shacknews.com/onearticle.x/62865

New Features:

Active Roster

Queue-Joining

Improved Voting System

Arena Playlists

Ranked and Social Combined

Streamlined Party-Up

Matchmaking Connection Options

Social Settings

Looks good.
The menus have updated graphics like the main game.

Ooh I like the background. But OMG I can't wait to get my Halo on again. Been awhile since I've played the Halo games, but I'm ready this September. Definitely one of my top games of this year, probably number 1 if Zelda doesn't come out this year.

Updated the OP with MP info. Good stuff in there!!!

looks pretty cool! cannot wait for the game!

this game will consume my life. May as well break up with gf now...

Hopefully it finds matches faster than the others. But I like the voting part

Do want. Nao.

Almost bought ODST today, just for this Beta

Looks like Urk has 104cR in image 3. Credits confirmed?

Also, in image 1, it has Bungie on the map image. Authors of maps on the images now? Custom content marketplace might be coming in the pipes from in-game in Halo:Reach, that would be awesome.

That.... is so damn sexy!