What is going to be the biggest feature in R2?

[Lockcaps]

Empire had Naval Combat, and greatly improved animations(First game with warscape)
Napoleon had attrition
Shogun2 had leveling up system for generals, reworked multiplayer, naval bombardment, 3rd-person gameplay and probably something else i forgot

What will Rome have?
So far, we know this:
Combined Land and sea battles(Big one)
Navies able to take over cities
"Unique cities"
Politics/relations will play a much more important role
More decisive battles
Unconfirmed/rumored/not really that big
Much bigger battles(10k+ men per army)
New graphics engine, looks(according to some journalists) "far far better than previous TW-titles"

But which is going to be THE feature that CA will promote the most to get old(and new) players into the game?

[Greve Af Göteborg]

Fully 3d tesselated incendiary pigs.

EDIT: Tbh, it seems like they're trying to cram a lot of new features into Rome 2 and are really trying to make it the game that defines the Total War series. So I don't think there's any big single feature that will get all the attention.

[a tw player]

Fully 3d tesselated incendiary pigs.

I'm not even joking when I say this; I can't wait to see this.

Not sure out of general awesomeness, or nostalgia from the days of sticking 20 units of incendiary pigs in a custom battle

[iWarsaw]

Have you all forgotten about the MOCAP!!?!? Imagine all the different MOCAP animations with the different weapons! It's beyond comprehension.

[Lord Baal]

Umm.. 3d bacon.. even better than the old 2d.

[Adreno]

Navigable rivers, should be pretty sweet

[PROMETHEUS ts]

Another feature seems that you will be able to customize your units equipment ... so create perhaps Sarmatian legions or Roman warhordes.

[DarthRuanek]

Navies able to take over cities

While navies will be able to play a role in city capture, you'll probably still need some ground forces to take cities. Though that may not be a huge issue if they allow you to use the military forces on the ships (as in Shogun 2, where each ship had its own boarding army).

Navigable rivers, should be pretty sweet

That sounds cool. Was it confirmed anywhere?

I'd have to say the things I'm looking forward to the most are intrigue and large scale battles.

[Asgaroth]

Every faction will be unique in culture and units.

The unique cultures sound very interesting to me, especially when there will be around 50 factions in game or more.

Apart from that :

Tbh, it seems like they're trying to cram a lot of new features into Rome 2 and are really trying to make it the game that defines the Total War series. So I don't think there's any big single feature that will get all the attention.

[Daily]

Destruction and chaos.

[Anna_Gein]

Diplomacy.
And Campaign AI since the two are linked.

[Hasforth9]

The new and totally improved AI


Just kidding, the super cool DLC's will be the biggest feature

[Geuvesa]

Personality, they mentioned that soldiers will have more personality and facial animations, like being nervous or excited, as well as interacting with each other. I always role play my campaigns and seeing my faithful troops relate to each other will make immersion far greater.

[Lockcaps]

On destruction: How destructable is it going to be do you reckon? Obviously it's not going to be Battlefield3 but i would really like buildings/towers to collapse in different ways depending on how it got destroyed. Also, being able to garrison troops in ruins would be nice aswell.

[Lord Baal]

What is going to be the biggest feature in R2?
Bella! Horrida Bella!

[Tritus]

The Pharoahs return, with legions of flaming desert axepigs.

[B. W.]

The ONE big feature in Rome 2 will be the massive improvement in many of the old features plus a few new ones. That just my take on it.