I am still hoping for some very handy things and things that make the game less time consuming, but those chances are very slim because we would see some of these in the free update.
Things like fencing tool, easily build roads/parking lots with road markings, improvement to path system, round roofs and more roofs in general, line tool and so on. With a line tool i mean something like a fence tool that can place any scenery item like streetlamps, hedges, pillars evenly with several options. Of course we need a whole lot more custom signs (not in gigantic sizes), fireworks editor improvement and things we never would expect that bring us something new like paint directly on walls with custom re-sizable brushes (based on vector images like flowers, squares, various art shapes), draw lines tool, click on wall and recolor the wall instantly.
I'm very curious to see what the new DLC will be. I'm hoping the DLC will give us a lot of pieces that can be used for several new themes (like chinese, vikings, alps, atlantis, disaster, jurassic, ..).
A prop line tool would be great. Sometimes I wish the devs would spend some hours playing Cities Skylines with mods. Imagine how much inspiration that would give them.
https://www.youtube.com/watch?v=Dt_VcBOuF4o