Nevah.
Despite Halo 4 not retaining the online popularity it had sales are still exceeding expectations.
I don't think we will ever see the end of Halo even if MS left the console business. They would most likely make PC versions or even *gasp* go on other platforms.

I don't play FPS but don't reckon people will be getting bored of Halo any time soon. In many ways it is like the Mario Kart of the FPS world, it's brightly coloured (thus not depressing to look at) and accessible while a high level of expertise is out there for those who wish to attain it.

People tell me they dig out Halo games frequently for a bit of competitive fun.

Weird question...
You may ask the same about Mario, God of Wars, Sonic etc...
If the game sucks at some point people will stop liking it but that's about it.

Many series have their niche. Halo is far more quality for the genre than Call of Duty and people are still sopping that game up so I think Halo is fine.

Never. Even if teens will eventually get fed up with him, Village People's lost member will always enjoy his 5-7% niche.

NEVER!