: At best it's a partial explaination, and one which some other games fighting
: over the same space seem to be less subject to the effects of.
All games are on decline. Even the big boys. In our Halo-preferred and Halo-isolated universe that we choose to live in because of our love for this game world, we don't many times take a look at other series. People elsewhere are talking about the decline of sales numbers, concurrent xbox live players and how the developers are taking the franchise in a direction the fans don't like.
I think the rumors of Halo's (or Call of Duty's, etc) demise are greatly exaggerated.
http://gamasutra.com/view/news/183066/
http://www.gamesindustry.biz/articles/2012-04-17-is-call-of-duty-really-in-decline
http://community.callofduty.com/thread/200659019#.Ul6yhRAwcRo
http://www.ign.com/boards/threads/mw2-is-what-really-triggered-this-slow-cod-decline.453133271/
- MacGyver10