Your avatar is so cute xitel :3
Anyway, Multiplayer has reached a peak recently, at it will only get higher but it will never overshadow Single-Player games. Multiplayer is an important factor for me, but almost all of the times I complete the single player mode before ever touching the multiplayer unless my friends push me to play a round online.
Also, maybe a reason you don't see any questions about the single-player aspect of a game is because it might not do much anyway, especially for sequals. In, let's say, Gears of War 2, we already know that Marcus is going to be fighting some Locust and stuff, we know he's going to fight some big guy and save the day, but what new features in the multiplayer mode will it add like the Meat Flag mode? Or, to put another game in the Limelight, how about Resistance 2? We know Hale's going to fight some Chimera and go all around the USA, but the multiplayer is vastly different from most other multiplayer games with different weapons and scoring systems AND has 8 player co-op with a separate story parallel to the Single Player mode. Or again, to put another game in the spotlight, how about Killzone 2? Well, we don't know much about single-player yet but we do know the person will be going around the Helghast planet, but for multiplayer they have this badge system that alow you to mix and match classes together.
That's not to say that Single Player games have died down, there are still plenty of good SP games out there, but I'm fearing that developers (especially for 360 games, not to sound like a fanboy or anything) are relying much to heavily on the success of their multiplayer aspect (IE, Halo, CoD4, Bad Company, Haze, Gears of War) than to put in a decent single player experience.