Sony and developer SuperBot Entertainment have gradually been unveiling new characters in PlayStation All-Stars Battle Royale, leading up to its October 23, 2012 release, and gamers have been yearning for more. The beta started a few days ago and from it has emerged a wealth of leaked information. The leaks are courtesy of game data extracted from the beta, so anything can change by launch. As is the norm, Sony "doesn't comment on rumors or speculation", so everything should be taken with a grain of salt.
For characters, we have the already announced characters, with Cole getting both a Good and Evil version, alongside newcomers Nariko (Heavenly Sword), Raiden (Metal Gear Solid), Ratchet (Ratchet & Clank), Sackboy (LittleBigPlanet), Sir Daniel Fortesque (MediEvil), and Spike (Ape Escape). Colonel Radec, Fat Princess, Kratos, Parappa the Rapper, Sly Cooper, Sweet Tooth, and Nathan Drake seem to be available to play from the get-go, with the other characters having to be unlocked by playing the game.
For stages, we have Alden's Tower (inFAMOUS), Black Rock Stadium (Twisted Metal), Columbia (BioShock Infinite), Dojo (Parappa the Rapper), Dreamscape (LittleBigPlanet), Franzea (LocoRoco), Hades (God of War), Invasion (Killzone), Metropolis (Ratchet & Clank), Paris (Sly Cooper), Sandover (Jak & Daxter), San Francisco (Resistance), Stowaways (Uncharted), and Time Station (Ape Escape). There is also an entry marked as "random", implying randomized stage selection as an option.
For items, we have Atomizer (Resistance 3), Baumusu Axe (The Mark of Kri), Boots of Hermes (God of War III), Dohvat Laser Designator (Killzone 3), Freeze Missle (Twisted Metal), Golf Club (Hot Shots Golf), Gravity Shield (WipeOut), Hedgehog Grenade (Resistance), Leech Beam (WipeOut), Murder of Crows (BioShock Infinite), Railgun (Metal Gear Solid 4), Razor Claws (Ratchet & Clank), RPG (Uncharted), Scythe (Fat Princess), Sonic Rift (ModNation Racers), and Spear (God of War).
For "Minions", presumably NPCs that appear on various stages, we have Athena (God of War), Captain Qwark (Ratchet & Clank), Dollface (Twisted Metal), Helghast (Killzone), Kai (Heavenly Sword), Kat (Devil May Cry), Keira (Jak & Daxter), Kiya (MediEvil), Kuma (Tekken), Little Sister (BioShock), Monkey (Ape Escape), Murray (Sly Cooper), Nix (inFAMOUS 2), Pierre (Doko Demo Issho), PJ Berri (Parappa the Rapper), Sackbot (LittleBigPlanet 2), Sam (Metal Gear Rising), Sully (Uncharted), Worker (Fat Princess), and Zeke (inFAMOUS).
Lastly, alongside AI difficulty levels of Easy, Normal, Hard, and Insane, we have what appears to be the available game modes: Arcade Mode, Capture the Flag, Challenge Trials, Character Trials, Countdown Attack, Free Roam, General Trials, King of the Hill, LAN Game, and Solo Play.
Again, this is all just speculation, but it certainly seems valid. That being said, twenty characters and fourteen stages aren't all that much, so hopefully these aren't the finalized lists, especially considering some Sony icons like Crash Bandicoot and Spyro are absent!