The Cities: Skylines team athas just posted an April progress update for the city builder, where they pledge "new features, gameplay tweaks, improvements and more fun" in the next major update.
Tunnels and wall-to-wall architecture is coming to player cities, but as this update is much larger they'll be keeping it "in development and QA for a longer time", by about a month.
So far two post-release patches have been sent out by the studio, which have "solved the vast majority of critical technical issues experienced by players." Other problems that are still troubling Cim Mayors will take longer to pin down as to their cause, and then work on a solution, or mods are wreaking havoc and that's hardly something the studio can handle.
"The next planned update for Cities: Skylines will be the most substantial to date, adding new features, gameplay tweaks, improvements and more fun stuff! Many of you know it as the "tunnels and wall-to-wall buildings update" that will eventually be added to the game for free."
Check out the fullblog for more.