Do you think that it's possible that it'll be made?

What characters do you want to see, use, and play in there? Personally, I want to fight Deathstroke and want him to be a usable character.

Will it beat it's predecessors?

of course its possible. anything is possible.  now whether it's probable or not is the question. i doubt it will beat it's predecessors but hey i could be wrong. 
 
Creeper of course has to make an actual appearance in this game or not be in it all.   
Tim, Dick and Selina all need to make their returns to the game and Cassandra and Jason should be allowed to join in on the fun. they all should be playable in a free roam mode or when new game plus is unlocked.

@PunkMastaFlex: there's actually a teaser hidden in the end of the game for a possible threequal Harley is pregnant

I personally think that given the 'prophecy' at the end of AC, they need to expand it into Gotham as a whole. Is it a bit ambitious in scope? Sure. But look at Rocksteady's record so far. It's not like they couldn't pull it off.

As for characters, Deathstroke would be fun, but dunno how they'd do that. I myself want to see them put Azrael in as a playable character because they had him in the second game.

There are some teasers in the game that point toward the son of Joker and Harley Quinn and (maybe) Hush.

Harley and Hush will have the most important roles based on the teases,no brainer it's Paul Dini writing and he loves both characters(much to my eternal dismay).They've also teased Azrael which is kinda cool i guess,i can see Manbat,Proffessor Pyg and Catman and Prometheus(or Wrath) joining.Won't rule out some Z-listers like Dr Death,Calendar man etc.

They'll prolly reuse Riddler,Croc,Mad Hatter(or Scarecrow) and possibly even Clayface.Robin,Nightwing and Catwoman will be joined by Batgirl(likely Cass),Azrael and maybe Jason Todd.

Deathstroke would be EPIC,and i would seriously love to see Bane and Deadshot being redeemed for their sucky portrayals.

@ZombieBigfoot said:

I personally think that given the 'prophecy' at the end of AC, they need to expand it into Gotham as a whole. Is it a bit ambitious in scope? Sure. But look at Rocksteady's record so far. It's not like they couldn't pull it off.

As for characters, Deathstroke would be fun, but dunno how they'd do that. I myself want to see them put Azrael in as a playable character because they had him in the second game.

agreed

Sorry, but: http://www.comicvine.com/batman/29-1699/a-clue-to-possible-batman-arkham-city-sequel-spoilers/92-638084/#20