Wow. Minecarts were added a long time ago. I think even vampires, werebeasts, and necromancers were after that. Sometimes vampires will migrate to your fortress without many easy ways to determine that they are vampires. It's quite rare, so don't worry about it too much until a dwarf is found drained of blood, in which case go look up vampire detection tips to try and find who it is. Werebeasts are just random naked people transformed into a somewhat dangerous form that might attack your fortress in a manner similar to megabeasts, except after an in game day they transform back into random naked person form and run away. If any of your dwarves get a scratch that breaks the skin and survives then they become a werebeast too and will transform for one day every month and then probably infect more dwarves. So read any combat logs involving werebeasts. Necromancers are only a concern if there's a "tower" on the neighbors screen when embarking. They'll arrive with armies of undead and raise any dead that they see to join their army. I don't think there's too much more other than what Shonai_Dweller said.
I guess attack and movement speed have been split now, allowing for whips to have slower attacks than any other weapon, though aside from that it doesn't have much fort mode relevance. Also armor and weapons now get damaged when in combat, which is actually pretty big. It's a bit too much as far as I'm concerned. I've seen bronze boots get entirely destroyed in a single fight. I've also seen a peasant with a silver knife completely break the knife trying to fight someone, so silver is probably a lot worse for weapons now. At the same time as that it was made possible for attacks with significant momentum to damage the joints of body parts they attack. This too is a bit excessive right now. Pretty much any hit can easily go breaking limbs regardless of armor. Invaders also show up wearing somewhat full sets of armor. It varies exactly how full they are, but it's normally nearly complete. Also there are a lot less invaders, because the world outside your fortress now continues to be simulated, so those invaders have to come from somewhere, and it turns out that the thing goblins used to do where they send sieges to your fortress every season, isn't very viable when you have to actually provide soldiers for those sieges. So they don't. You'll get some, but nowhere near the amount you used to. So actually a lot of things have changed other than what was described. Yeah there's a lot. You should probably check any new wiki pages.