Hi, I am the White Mamba Overlord of our group the ODSM.
We are not a clan, and we don't play the game for competition. Instead we play for fun, and to hang out with friends. If you are interested in joining go to our group homepage and sign up. Membership is open.
We are mostly a Halo 3: ODST group for help with achievements and stuff, but we also will play a lot of Halo 3 matchmaking.
I personally think that the only thing that will be in common between the book and the game is the fact that it is based on how Reach fell. I don't think Bungie would go and tell us a story we already know.
Besides; Spartan 259 (I think that's right?) and 320 are never mentioned in the book. I am pretty sure they are 2 of the 5 main characters.
I do hope however that there will be some small connections between the two stories. Maybe a radio transmission or something.