Here's what I extrapolated so far from articles that talk about or make reference to Gallente...this isn't everything new there but just the ones I picked.
Caille- The Federation is possibly a "colonial alliance" in the same way as a ME-style Systems Alliance (ie. supranational authority)
- The Federation capital was moved from Luminaire to Villore at some point
- Gallente Prime has its own military independent of the Federation.
- Gallente history includes an "Age of the Ancients". Caille has a Roman-style ruin site of white marble called the City of the Ancients? Also 'Sanctuary of the Seventh Goddess' gives clues to Gallente religion.
- Caille is the capital of the Kingdom of Central Garoun; Gallente Prime still divided into nation-states.
- Fashion models may have previously been slaves or trafficked.
Solitude- Solitude was previously independent and a sovereign area of space, then voluntarily joined; Federation equipped to peacefully absorb new territories.
- Federation planets prefer to rely on "highly-trained police paramilitaries" or PMCs for groundside security
- Federation is heavily decentralized. Planets retain legacy systems (see previous Gallente Prime example)
- Federation is minority-majority
Lirsautton- Jin-Mei were at an interplanetary level of development before Federation first contact. Had colonized two planets. Technologically advanced?
- Traditional Jin-Mei name for Lirsautton is Mei-ha. Chakaux (p3) is Hulang, Chandeille (p5 homeworld) is Tei-Su. Changed to support Fed. Possible Jin-Mei obsession over Gallente culture? (ie. modern Japan and US?)
Fed Marines 62 B Company- There are youth corps contingents of the Federation military
- Gallente special forces have a presence on Caldari Prime
- Highest overall decoration for Gallente citizens/soldiers is Hero of the Gallente Federation? (Hero of the Russian Federation trolol?)
There's more stuff, but I'm sleepy atm and cbb to look it up. Some real interesting stuff here. Post some of your stuff if you find anything interesting.