Voiced character (limits role playing potential and dialogue sequences, e.g. previous text-box based responses allowed for more creative freedom as they didn't have to record each individual line and could introduce various dialogue paths.)
Limited dialogue wheel (Becomes fairly binary choice, e.g. good/bad/neutral. Same reasoning as above really.)
Skills and perks combined into one (might limit creating truly unique characters. Again, limits RP potential.)
Removed feature/"streamlining" (absence of hard core mode, various mechanics tweaked or removed entire according to leaks (repairs, karma, reputation (...like Skyrim...))
Some things are exactly the same/carried over from 3 (lock picking, hacking, etc.) Same engine quirks most likely, and just Bethesda in general (poor writing, animations, etc.)
I'm personally worried it's not gonna be much of an actual RPG, and becoming fairly "casual" (they've seemed to carry over a lot from Skyrim unfortunately.) Understandable, but...