Traidtionally, the issue that comes up is between Awakened and Non-Awakened, because neat new toys (Guns, EmoToys, whatever) can be used by magical characters and non-magical as well, which fails to close the gap. New Cyber can close the gap, but not terribly far, simply because there's a hard cap of 6 Essence.
So, new guns, new armor, new toys... nice, but not a HUGE thing.
New Cyber or Bio can be a game-changer, so is very, very essential to walk softly on.
Vehicles are ... interesting. Aside from the ongoing joke that RIgger books end editions, the truth is that vehicles are both needed to sustain the world, but are some of teh least-used bits of gear. Typically, "How is everyone getting there?" is answered "We get in Bob's van" or, "Well, me and Tony have bikes. Jill has a car, so everybody else piles in with her. Wait, Frank won't fit. Frank? I guess you're on the subway buddy. Tough luck."
Vehicle rules are never vetted as well as the others, due to being a small chunk, and tring to make a vehicle book often falls flat ... and is ALWAYS art-heavy. (Art is far more expensive than writing.) You can tell people about Pocket Gadget #7 and the nod along and don't need a pic, but when you mention a new Ferrari for 2073, you'd better have a picture or people start breaking out pitchforks.
So, vehicle crunch is one of the few areas that need some real expansion. There's room for some minor crunch after that, detailing unique rules for Critter X or Decking Program Y, or adding a dozen new bits of minor gear somewhere (For example, if a new Rocker book came out, rules for instruments and performingw ould be needed, but a page, two tops, should handle it)
Fluff, however?
I can never get enough fluff. It's what defines a setting!
