It appears that as of the addition of the new free DLC for Red Dead Redemption that Rockstaradded today, the multiplayer servers are offline. When trying to connect, the loading screen never goes anywhere and you can voice chat with others who would be spawning near you (mind you if the FUCKING thing worked.)  Most people can not get online as seen on other threads and this does not seem to be limited to Xbox Live, as it's fubar on Sony's PSN as well. No official announcement has been made by Rockstar, Microsoft or Sony regarding the outage.

Marvel Moves Forward on “Doctor Strange” Movie: "With Captain America and Thor doing solid box-office business and The Avengers on the horizon, Marvel is looking to continue its streak of box-office success. The studio is developing a script for a potential Doctor Strange feature film, reports MTV News.