As a teaser, here the keywords for the megas. I hope this is ok
Ares: Struggle (as discussed)
Aztechnology: Death (Its inevitable, don't fear it, enjoy life instead)
Evo: Evolution
Horizon: Consensus (bland, forgettable entertainment everyone can agree on)
MCT: Order
Renraku: Communication
S-K: Power (Letting its media part mostly run itself and only placing things here and there which then ripple through the entire industry)
Shiawase: Family (So family entertainment. They are also very good with Simsense)
Spinrad: Radical ("What would Johnny do?")
Wuxing: Balance
The AA media companies are:
Cross: Whats left from CATCo
DeMeKo: Masters of the niche market
Providence: Polish company with heavy catholic influence
Sony: Games