After about 6 years of playing, this is still one of my favourite games. I love Dwarf Fortress for the simulation, watching the dwarves have lives, and I can't get enough of how much you've recently fleshed that out. And I know there may not be a new release for a while after this next one so I wanted to mention some of the things that I really want to see that may or may not be easy things to add in so I'll jump right into it;
1) A squad function to 'rescue' a dwarf. The squad will attack anyone who is attacking the unit to be rescued, one person in the squad will grab the designated dwarf and carry them to the hospital, with the rest of the squad following close around the carrying dwarf.
2) Now that dwarves can leave the map, it would be great if they could be summoned or called away from your fort for a variety of reasons, such as; The yearly competition games that go on during world gen, an event could occur with the liason asking who from your city will be competing this year, with larger civs perhaps having several events. Royal weddings, diplomatic dinners, and simply dwarves asking to leave, either permanently (Maybe to join a master or family, or for a personal adventure) instead of just getting mad.
3)Performer types (Bards, Poets, Dancers, Performers) take on students after world gen, like scholars. As well have them continue to write new poetry, songs, and dances, and create new instruments.
4)I often have dozens of books written about HOW to write about a certain subject, and rarely ever books about the suggested subjects. IE; comparing civilizations, personal adventure story, biographies, etc. I'd love to see more actual books written by the dwarves, fewer guides.
5)More use from temples. There are now pilgrims, how about priests? Visits from the High Priest of a dedicated temple would be nice. Maybe they even stay, like a new member for the Nobles and Administrators page if your temple is holy enough. Maybe even a visit from your god, or some demon impersonating him. Adding in pews or prayer mats too would be nice.
6)Cleaning as a fulltime skilled job. I often have vomit paths. My forts are often in need of a full-time Custodian/Groundskeeper.