As long as your Xbox 360 is connected to the internet and you have xbox live GOLD membership then yes you can play on xbox live with Call of Duty
Yes it came out as a arcade game in the xbox live market place when mw2 was released.
Yes
Yes the Xbox 360 game does work on the arcade
You have to have Xbox Live if you have an Xbox
Xbox: Xbox Live arcade PS3: PlayStation Store It is also available to be bought on a card in Gamestop and other video game retailers.
it depends where you get it
If you do not have Xbox live, there is no need to have Call of Duty Elite. The COD Elite gives you a huge data profile about your online stats, matches etc. If you do not have xbox live, there are no stats to gather. The Call of Duty Elite will have a yearly cost, this will be a separate payment from Xbox live.
Yes you can even if you can not add dlc
Xbox Live Arcade was created in 2004.
No, you can not download maps for call of duty five without being on xbox live.
yes
escalation is out for xbox and ps3 get it soon