Yup, saw the scans of P4 Golden.
Well here is all the info I have recompile from the 2 tittles:
P4 Golden (Vita):
- 3G and Wi-Fi support
- New event scenes
- Added Personas
- Added character outfits
- New character Marie, voiced by Kana Hanazawa. She's a "mysterious girl" who appears before the main characters.
- When you're about to die in a dungeon, you can send a message seeking help to other players. It's not specified how this system will work exactly.
- Additional anime movie scenes, with new voices
- 1.5 times the voice of the PS2 original
- New song for the opening movie
- An element that has been highly requested by fans
P4 The Ultimate In Mayonaka Arena AKA Fighter (PS360/Arcade):
- Game is a Sprite base 2D Fighter done by BlazBlue Team
- The Persona Team is highly involve in the development
- You can say this is a Persona Team X BlazBlue Team project
- Persona 4 Fighter takes place 2 months after P4
- Persona 3 cast are in it
- The story goes that Teddy decided to do a fighting tournament in a TV program "P-1 Grand Prix".
- You can select the kind of magic/spell your Persona will use in battle.
- Characters Confirmed so far: P4 MC (Yu) (Fool), Chie (Chariot), Yosuke (Magician), Aigis (Fool).
- Others characters seen but not 100% sure: Yukiko (Priestess), Kanji (Emperor)
- Release Dates: Arcade (Spring 2012), PS3/360 (Summer 2012)
So it seems Persona 4 Fighter is canon and I assume it will play like Jojo Bizarre Adventures to some extend.
P4Golden seems to be a hint to Catherine, since Catherine takes place in a TV Channel called "Golden Productions" and since P4 takes place in the TV World I can see some links in there. Also P3P featured Vincent in it as a cameo, so who knows.
P4F Scans (Copy and Paste URL to your browser bar):
http://gamingeverything.com/wp-content/gallery/persona-4-fighter_1/p_4_fighter-1.jpghttp://gamingeverything.com/wp-content/gallery/persona-4-fighter_1/p_4_fighter-2.jpghttp://gamingeverything.com/wp-content/gallery/persona-4-fighter_1/p_4_fighter-3.jpghttp://gamingeverything.com/wp-content/gallery/persona-4-fighter_1/p_4_fighter-4.jpghttp://gamingeverything.com/wp-content/gallery/persona-4-fighter_1/p_4_fighter-5.jpghttp://gamingeverything.com/wp-content/gallery/persona-4-fighter_1/p_4_fighter-6.jpgEDIT: Updated the info, specially the P4F info.