The REACH beta managed the near impossible task of making me care about playing the multiplayer again. I really loved the MP in the first, then grew tired of it as time went on and sequels came to pass. I never hated the multiplayer mind you, I just played Halo mostly for the fun co-op and interesting story (shut up, it's good if you read the books).
But then comes the Reach beta and I'm once again engaged by the multiplayer. Not the least of the reasons why is the social options available to tweak the type of players you are going to be matched with. The option to look for other players interested in a nice, respectful, quiet game makes a lot of difference. Of all my games during the beta, I only had one or two really obnoxious players who managed to sneak into the games I was in. Imagine it. No yelling at the top volume, no racial slurs, no "press X to veto" every bloody game even if it looks like a fun match... ugh.
I've already pre-ordered the game. And I'll probably get one of the collector edition versions, though the "Legendary" edition is priced way above its worth so I'll likely end up with whatever the middle one is called.