As far as i'm aware, you are still ranked, but you lose all the online functionality, as in you can't see your game history online, as you can with Halo 2, 3, ODST and Reach. Put it this way, you can see your Halo 2 online record from 5+ years ago, but from December 16th, you won't be able to see a game from 18 months previous (If you played on the very first day it came out). I think i'll play some before it goes bust. I'll be honest, I think it's sad to see it go not because it was brilliant, but because it shows how microsoft doesn't care for this game or it's fans.