They were working again early this morning when I was playing. There's very rarely a big release without some sort of technical issue though, so it wasn't a big deal for me. I can't wait for them to drop more multiplayer game variants. SWAT is already confirmed by IGN, and hopefully they'll put in more specific Slayer games like Snipers.
I'm loving the campaign as well, but multiplayer is obviously where the replay value is. I wasn't a big fan of Halo 3, but Reach was my favorite shooter...probably ever? Maybe? I haven't made a decision yet - like it matters - but this may replace it as my favorite Halo game. Guns like the DMR just feel so responsive and are fun to use. The promethean weapons in campaign look so damn cool. You pick them up and they construct around your hand. Bad ass.
Not sure how I feel about the loadouts. Halo has always been about on-map weapons. Now it's more like Halo: Modern Warfare. That's not necessarily a bad thing, because the game is still hella fun to play. And ordinances mean you can still get the other weapons. And from time to time it seems random weapons do drop on the map. There's also a "classic" mode you can play in custom matchmaking, to play with weapons on the map. So I think there's probably something there for everyone. Really, really great game.