Last Batman game for Rocksteady, will work on something totally new next.
There will be a brand new villain, something made by Rocksteady that they say will be the ultimate test for Batman
Batmobile can be called at any moment with a button.
The city streets are much wider to allow for the batmobile. You will rocket jump off ramps and do all sorts of cool maneuvers.
You can eject jump out of the batmobile right into a super fast glide straight through the glass of a building to knock out enemies. They said glass breaking will be a big new thing.
New moves include being able to use all your gadgets during flight. You now have a counter throw where you counter a guy and throw him into another guy. A new quick ground takedown. A quick backflip where you then throw a batarang in an enemies face.
For the predator sections you can now chain takedowns of up to four enemies. For instance pop out of a grate and take one guy, jump to the next and so on. You can now enter grates from a distance, he will automatically do a jump or roll to enter them.
Riddler challenges seem to be car based. The first one has you enter a sort of Riddler race track where you have to activate walls and ramps, when you activate one another closes so as you drive you have to be constantly turning on and off these ramps as you navigate the course.
Batmobile fires missles and stun guns. It destroys anything it touches so if you bump into cars the cars go flying. It's basically unstoppable.
Story is that after Joker's death all the criminals decided to work together and their plan comes together this night where they plan to kill batman. The article talks mostly about Scarecrow, he scattered bombs throughout Gotham.
Oracle will play a larger role, you get to visit her base and talk to her, tons of batman easter eggs included.
Kevin Conroy is Batman, all the previous voice actors are back.
Gothom City is 5 times bigger than AC. Split into 3 areas. NO LOAD TIMES at all, entering buildings is seemless.
They spend a bunch of time talking about how detailed the models are, one character has more polygons than the environment of Asylum.
Batman will start off with the old batsuit and upgrade at some point in the game.
It says it is running on their modified Unreal engine.

All quickfire gadgets can now be used during flight.
- Combat tweaks (note: Not enough time to go over these in detail. for example, you can throw by tilting left towards the opponent and hitting counter)
- did I mention the screenshots are gorgeous?
- Arkham Knight isn't just the name of the game.. it's also the name of the [new] villain.
- Fear Takedowns. ie, burst out of grate, action slows down allowing you to target another goon for another attack and so on. Can be used on groups up to 3 as long as they're close enough together and no one has already spotted Batman.
- They seem to try to tackle the old school Arkham issue of "open door - black screen loading"
- The game looks gorgeous. Huge.
-"This is a single-player game. There is no multiplayer."
- You can launch into a fast glide from the Batmobile just like the trailer.

-No more pre-rendered cinematics everything is done in engine
-The larger riots can have up to 50 people flipping cars and looting stores.

Characters
-Things such as Gordon's trench coat and Batman's cape now have Apex cloth physics. They react realistically to changes in wind and movement
-When it rains rains bead of water run down Batman's suit tracing every groove
-The wrinkles on Gordon's face crinkle as he talks

The City
-The city is as detailed as ever with realistic moving clouds with the moon shining through
-Halloween characters and balloons litter the street adding a creepy vibe
-Neon signs of the various shops shine brightly around the city
-The skyline has helicopters and blimps flying through it
-Steam puffs out of the sewers in a realistic way

You can now use the linear launcher on anything to create ziplines. This is done in mid flight so you can quickly land where you want.
All enemies now have the ability to grapple Batman, not just big guys.
Roads wont have many vehicles, just some thug cars and cop cruisers
There can be enemy riots, up to 50 enemies on screen at once.
More Riddler type challenges than just racing.

Gamespot.com wrote:Batman: Arkham Knight for Xbox One, PS4, and PC Delayed to 2015

This year's big Batman game, Batman: Arkham Knight, is now next year's big Batman game. Warner Bros. announced today that Batman: Arkham Knight for Xbox One, PlayStation 4, and PC has been delayed and is now expected to launch sometime in 2015. Previously, the game was scheduled to launch this fall.

Why the delay?

"We just want to make this the best experience that we can, and that takes time," Rocksteady Studios marketing manager Guy Perkins told GameSpot. "We feel that we have an absolutely awesome game in the works, and we want to make it as great as it possibly can be. We just need more time to do that. If we didn't give the team more time to do it, then we would be releasing something that we weren't happy with. We want to make sure we're absolutely nailing it 100 percent."

Batman: Arkham Knight is skipping the Xbox 360 and PlayStation 3, instead coming to Xbox One, PS4, and PC. According to Perkins, Rocksteady's full vision for the game could not be realized on last-gen hardware

"The Batmobile is one thing we just couldn't do on previous gen. It's not just a case of having a car, it's a case of building a city where the car feels at home," he said. "So if we were to try and bring the Batmobile into Arkham City, for example, the streets aren't conducive to that driving experience. You have to create a much bigger environment to house the vehicle."

"Gotham City is five times larger than the game world of Arkham City." -- Guy Perkins

"Gotham City is five times larger than the game world of Arkham City. And by virtue of having a bigger city, you need more memory and more horsepower to just make that happen," he added.

Not only that, but the detailed character models for Batman: Arkham Knight would be too much for last-generation hardware, Perkins said. "The details on the models we have is insanely huge at this moment--the detail on Batman alone is phenomenal," he said. "Having these current-gen platforms [Xbox One and PS4] allows us to really flex our muscles in terms of art and animation, and we're building everything to make it look as good as it possibly can. The beauty is our engine team can now say yes to our artists; before they were always struggling with what they have available. But now it's more a case of, 'What can't we do?' and, 'Where can we push it even harder?'"

Asked if the technical performance for Batman: Arkham Knight would be the same for the Xbox One and PS4 versions, Perkins said, "We have a benchmark in mind, and we want to give gamers the best experience. We are optimizing at the moment; it's always a challenge, but we want to get to the best place."