ODST is finished. I stand by what I said, the missions where you are the rookie are downright awful and boring. You're sloooooooowly plodding through dark ass streets just to make it to a marker to initiate a mission that is actually good. All the flashback missions were awesome. I wasn't a huge fan of the escort stuff at the end, protecting that turtle looking thing, but the Warthog sequence made it much better. Overall a good game. I forgot Fillion was in Guardians, I was very surprised to see him in this game. Apparently his character is an Easter egg in Reach as well but I don't remember if I found him or not.
I'm six or seven missions into Halo 2 now, just killed the Heretic or whatever. The Covenant stuff is very cool, way more interesting than anything happening on the human side so far. I don't remember where this Arbiter story goes, it's been too long.