A lot of people have been making this statement recently in the run up to the release of Battlefield 3 and Modern Warfare 3. Even EA claimed that CoD would die within "2 to 3 years". However, I don't believe that this is true, and that so long as they keep up what they're doing  their games will continue to sell ~15m combined well into the future.

Online

There is no denying that much of the reason for CoD's success comes from it's addictive online system that it very easy to get into. Even if people start to dislike the franchise a little, they're unlikely to stop playing - because everyone that they know will be doing the same thing. If there was a group of 10 people that liked to play CoD online, what are the chances that one or two of them would randomly stop buying CoD because they're tired of it? In this regard, CoD needs a huge social networking campaign getting lots of people to stop buying it at once for it to have a decline in sales. In other words, the greatest risk to the CoD franchise is competition - not people getting bored of the gameplay.

It's not like Guitar Hero

A lot of people refer to the downfall of once-popular franchises like Guitar Hero and Tony Hawks to show how capable Activision is at running franchises into the ground with overreleases etc. However, the franchises are very different, and I very much doubt that they'll decline in the same way. Despite Activision coming up to releasing it's 7th CoD title in this console generation alone, they have been far better spaced out than those of Guitar Hero (who I believe had 3 releases in one year). Not to mention that Guitar Hero required the  purchase of overpriced guitar controllers, and generally didn't have the same success as CoD in the first place.

Mass Appeal

People like killing things. Playing CoD is like releasing your inner, primitive self - and in a fun, competitive environment. Unlike the story of Tony Hawks, the appeal of grouping together to take down the enemy is not going to die in the same way that skateboarding went out of fashion. There is no denying that CoD has a massive appeal to all sorts of people by concept alone, and then adding the addictive level/ranking system alongside other features like killstreaks and perks mean that the average consumer is likely to get many hours of playtime out of each release. People don't mind paying $60-90 a year if they're getting hundreds of hours out of their purchase.

All in all, there is a lot of doom surrounding the CoD franchise at the moment, but I don't feel that it's going anywhere. Activision have hit a goldmine - and unfortunately, unless the competition comes up with something better and with more mainstream appeal, this is going to continue to be the case well into the future.

Along with the never-ending COD threads..

I agree, I don't think it will ever 'die' but I suspect that Modern Warfare 3 will be the last game to outsell its predecessor and the CoD series will continue to do well but will have hit its peak.

The reason why Guitar hero/Tony Hawk died was because music games with instruments and skateboarding was losing his appeal. Sure people went to get Rockband and skate but those two games are getting killed fast.. Will we even see a new Skate?

COD will die it's not a matter of if but when and how.

"Everyone dies,
everyone lies."

I dont know if COD could completely die. Maybe suffer a similar fate to Medal of Honor.

You're right. It may get smaller, but it'll never die.

COD is like Madden, but ten times bigger. Fans buy it every year looking for the same thing. You'll never hear a Madden fan saying "hey, they didn't change the gameplay at all". All they care about is updated rosters, better graphics, etc. Just like COD fans, they want a few new perks, new weapons, better graphics, etc.

It could die, sure. Look at NBA Live. That dies because a superior competitor came along in NBA 2K. Now the only way COD is going to die down is if a superior FPS comes along and releases yearly. That FPS is not Battlefield.

In order for a FPS to outdo COD, that FPS would need to have local multiplayer, pick-up-and-play accessibility, have yearly releases, and probably some more things I can't think of.

It'll die when a better FPS game comes along. It happened to NBA Live and it was going to happen to Madden until EA bought the rights to the NFL and NCAA licenses.

well it just goes to show not everyone sees a game with low quality.

its broken but why fix it when the sells continue to climb every yr?

Let's wait for next gen to shake things up. That or yearly console counter-strike releases