You can already use Routines in Google Assistant, but you've so far had to tweak "ready-made" examples to fit your needs instead of creating your own from whole cloth. That might not be a problem before long -- 9to5Google has discovered code in the latest Google app beta hinting at upcoming support for custom Routines. You can tell Assistant both what command to use and what actions to perform when you say the magic words. You could have a "movie night" command that dimmed the lights and warmed your home, for instance.
The beta also refers to pinned sports scores that would appear while you use other apps, letting you keep tabs on that all-important match without having to ask Assistant or find the relevant info card. Other code helps explain how gestures for Pixel Buds will work: you could tell the double-tap command to do something besides check notifications, or triple-tap for manual control. You could even turn off the Pixel Buds just by removing the right-side earpiece.
As with any hidden code in pre-release software, there's no certainty that the features are imminent, or even that they're guaranteed to arrive. Updates sometimes linger in beta for months or get cut entirely at the last minute. All these updates are very practical, though, making them more likely a matter of "when" than "if."