No magic yet. It'll come next arc, in about 2 years.
Main new features are artifact generation and tracking in worldgen, and ability to raid/pillage/raze other sites in fort mode, sometimes enticing them to send sieges in return. The civilization screen has been expanded to accommodate this -- instead of just a list of civilizations you have encountered, it has a map that you can look over. Razing, if successful, will turn the target site into a ruin, and pillaging will allow the dwarves you sent to bring back at most one item or animal per dwarf (both kinds of loot are toggleable in the mission menu.) You can also quest for specific artifacts in raids, and can encounter artifact questers in adventure mode (and become one yourself if you get a quest from your lord). You can steal artifacts in adventure mode as well.
Kobold caves have also been expanded. They now have many different rooms -- some have poisonous beasties such as giant cave spiders, others are covered with weapon traps coated in the poison from said beasties, as well as treasure rooms that can contain artifacts.
Modding-wise, [ANIMAL] tags in entity definitions have been implemented; basically allows you to give civilizations access to and control their usage of various animals that you specify. You can specify [ANIMAL] blocks using either race & caste or creature token. Example tags that you can specify for [ANIMAL] blocks are [ANIMAL_ALWAYS_PRESENT] (civ always has access to animal regardless of biome restrictions) [ANIMAL_ALWAYS_PET] (the animal is always available for adoption) and [ANIMAL_ALWAYS_MOUNT] (animal is always available as a mount in sieges.) There are ALWAYS and NEVER versions of most animal tags.
That's basically it, so far.