Characters
Fully playable and new:
1. Sabo
2. Doflamingo
3. Issho aka. Fujitora
4.Tashigi
5. Rob Lucci
6. Gecko Moria
7. Emporio Ivankov
8. Magellan
New, but of unconfirmed status (possibly support)
1. Alvida
2. Captain Morgan
3. Captain Kuro
4. Bellamy the Hyena
5. Jesus Burgess (also: Pirate captain enemy of Burgess' fighting style, Wrestler pirate)
6. Wiper
7. Mr. 1 Daz Bones
8. Oars
9. Hody Jones
10. Halfgiants
Updated Gameplay and Attacks:
1. Usopp
2. Zoro
3. Sanji
4. Nami
5. Luffy
6. Law
and possibly alot more to come.
Confirmed Story Arcs (check brackets for character introductions)
1. Orange Town (Zoro/Captain Morgan)
2. Syrup Village (Usopp/Captain Kuro)
3. Baratie (Sanji/Don Krieg/Mihawk)
4. Arlong Park (Nami/Arlong)
5. Loguetown (Ace/Tashigi/Smoker)
6. Drum Island (Chopper/Wapol)
7. Alabasta (Vivi[?]/Crocodile/Nico Robin)
8. Jaya (Bellamy/Burgess/Blackbeard)
9. Skypiea (Wiper/Enel)
10. Water 7 (Franky/Lucci) and 11. Enies Lobby (Robin)
12. Thriller Bark (Moria/Kuma/Oars/Perona[Preskip?]/Brook)
13. Sabaody Archipelago (Law [preskip?], Kidd [?], Kizaru)
14. Impel Down (Magellan/Jimbei/Ivankov)
15. Marineford (Whitebeard/Akainu/Shanks/Aokiji/Doflamingo [maybe])
16. Fishman Island (Hody Jones)
17. Dressrosa (Sabo/Doflamingo/Fujitora)
Punk Hazard and Amazon Lily have not been reached by the progression of scans, going chronologically [currently at Thriller Bark]. They haven't been teased in any way but are a possibility.
Gameplaywise:
-All final hits of a combo previously only possible during style action mode are now fully integrated into the standard moveset of every character.
-Kizuna Rush replaces the Style Action mode: similar gauge and look upon activation, but you are now able to call up to 4 support characters in for attacks. Having them tag in for you as was the case in PW2 is not possible and has been replaced with a comic-esque combination attack between you and your supports.
-Boss battle cutscenes return. Whether they will feature Quicktime-events or not is unknown as of now.
-It looks amazing so far. No lag, more enemies onscreen, smooth textures. PS4 and PC have really done this game a favor.