The Google Maps API team maintains a set of APIs that many third parties rely on to power various functionality within apps. While the team often publishes blog announcements for major revisions and feature additions, minor tweaks and bug-fixes are often made without notice to the developer community outside of Release Notes updates. Since minor tweaks can require programming alterations by a third party, Google has bridged the gap with the addition of RSS feeds to the Release Notes.
The 9 available feeds covers all Maps and Places APIs. While Google didn't specifically mention the addition of other APIs, one would imagine if the project goes well, RSS feeds will expand to additional APIs from the Maps team as well as APIs from other teams within the Google family. Many developers have been caught off guard from breaks that resulted in using outdated API versions (even if the change was seemingly minor). Google's RSS feed strategy is an attempt to eliminate this common problem that has API integration relationships since the inception of API partnerships. Check out the blog post announcement to subscribe to the RSS feeds.