The announcement is here.
Today is launch day and we have been given the news to share that these tools exist, and also some stories that we may have been working on.
Google wants Earth to become a “storytelling canvas” that lets you “create a map or story about the places that matter to you.” These creation tools are accessed by clicking the new “Projects” tab in the sidebar and creating one.
After adding a location by search or dragging a pin, you can attach images, text, videos, and customize other properties, including colors, pins, and choosing the right 3D view to frame. In addition to places, you can draw lines, shapes, and Street View.
All work is saved to Google Drive and supports standard collaboration. Once complete, there is a “Present” view that flies you from location-to-location while displaying all your notes on top. In addition to the web, the final project is available on mobile and tablet devices with the Google Earth app for Android or iOS.
I have started to produce a story on South Georgia for my first attempt, as part of a resource that I am producing for the South Georgia Heritage Trust. This has been blogged about elsewhere.
Here's the link to the story so far.
The tools produce a similar outcome to that produced with ESRI StoryMaps, but with variations in imagery and functionality of course. The two tools aren't necessarily in competition and it remains to you to consider.
Check Richard Allaway's examples here: revising extreme environments.