It really should have some sort of variety. Rush is fun.

I love conquest, however there should be some more modes for sure.

They need a Titan Mode equivalent. Maybe with navy ships?

Given that this is one of the core franchise's releases, my guess would be that Conquest mode is the centerpiece.  However, with the ability to destroy virtually anything, that could very easily be a difficult thing to fully accomplish.  I keep thinking about Strike at Karkand in the Frostbite engine, and while it's fucking awesome every time I dream about it, there's a reason that map worked so well on BF2.  It was a great map size on 16, 32, and 64 player rounds, but it was also very well laid out for offense and defense.  There are so many Alamo spots and frontlines in the game that it's tough to think of those with the ability to blow all that shit up. 
 
In the end, though, it also means that Rush mode could work like a fucking charm on that map!  So many places to push from, so many places to Alamo up, and with the improved sniping from the Bad Company games, I can only imagine how vicious the whole thing could be. 
 
I just hope that Conquest isn't that shit they tried to pass off in Bad Company 2.  That shit was TERRIBLE.

There will definitely be more than classic conquest. Probably rush using fewer players (so they can use the same maps one section at a time) like Bad Company 2. Hopefully there will be some variety and maybe a new mode instead of the standard variation on CQ capturing rules.

I think they should get rid off the squad stuff and the hardcore mode, at least on consoles. That only splits the playerbase (I know this is not an issue on the PC due to the server browser.) I think Rush is a great mode. It works well on low player count, because it funnels the action a bit more.

Killzone 3 actually adds some interesting things to this type of mode. Piecing stuff together with litte cinematic pieces, and adding map specifc mechanics. On the beta map the defenders release nerve gas on the attackers. These can choose directly go for their objective or secure a computer core to hack into the gas fan control to make the attack easier.

That is a cool element and it would translate well into a Battlefield Rush mode.

"Several" as in... 2 extra modes?

There's going to be more than just conquest.  Hopefully they'll include a rush mode as well as some new game types.

The BF series already had new modes. At least since 2142 with Titan Mode so I would be surprised if there weren't more objective based modes in BF3.

FYI this poll is 1 year old

Maybe they'll introduce  new mode. All I know is there better be something resembling rush, because that's a refreshingly original game mode for online fps.

Conquest is a classic but i had tons of fun with rush as well. They shouldn't be afraid to try new things.

it'd be stupid to only have one mode.
 
conquest (classic)
Rush (still good)
and Titan, with aircraft carriers being the "titans" with small connected strip of islands in between maybe.
 
wake island being made into a titan mode style map? YES PLEASE!
 
besides, Titan mode is basically a more complex and dynamic version of conquest anyways.