III.B.2: Ability to send your army or part of your army out into the world map (part of Core27)
Since the dev log doesn't explain a lot about the various Cores, I assumed something like this was in the offing after a year and a half of development. When exactly is it supposed to come in anyhow? Maybe the wiki has something about the cores...
I recently read through the dev log from the d40 release and basically* what happened was he chose to break save compatibility to fix some fundamental issues preventing further work on the Army Arc. Now, because breaking save compatibility is a Big Deal he wanted to fit in as much fundamental work as possible at the same time. In hindsight this proved to be a massive undertaking and significantly slowed the project. This has been acknowledged by Toady as a harsh lesson.
Where things stand now is he's finally finished the save breaking work, for now at least, and laid the foundation for relatively rapid development of more Core features. So we should see a cycle of bug fixes for awhile, followed by much smaller chunks of new functionality.
*I kinda forget the details, and old dev log is gone now.