Tonight, Google announced an updated Maps SDK that adds ground overlay support and makes API keys available to all developers via the Google API Console. Previously, developers had to register and wait to be granted access to keys.
Now that keys are freely available, it's likely that more developers will use Google Maps in their apps. Some developers may decide to allow users to choose between Google and Apple's maps, much like the recently released Sunrise calendar app.
Google has also included a sample app in the SDK that developers can use to learn how to use Google Maps in their apps and released a video (above) demonstrating some of the SDK's features.