Update 1/5/16: The former CTO of Mozilla weighs in on the Android/OpenJDK news, and his view is quite negative, but let's remember he was working on an Android competitor, Firefox OS.
Update 1/4/16: Gluon, a company that produces a Java API for building cross-platform mobile applicaitons, had some deeper analysis of this news on their blog recently. Here's a quote:
2.1 The ‘move’ from Harmony to OpenJDK
From the commit message in the Android repository, it seems Android will at least use the Java Class libraries from the OpenJDK project. It is not clear whether Android will continue with its ART runtime, or if it will switch to an OpenJDK engine (e.g. HotSpot).
2.2 What does this mean for OpenJDK?
The key message is that this makes OpenJDK even stronger and more important. Most of the big players in the Java world are part of the OpenJDK project, and contribute code into it. The list includes Oracle, IBM, Apple, SAP and Twitter. The companies participating in OpenJDK agree on a standard and compete on products and services leveraging the standard.
News broke this week that Google will be aligning its Android mobile operating system with the OpenJDK project. Although some of their code already used OpenJDK, Google says that the next version of Android, currently called “Android N,” will remove all of its Apache Harmony-based libraries and replace them with OpenJDK-based ones. They’ll also be required to share its implementing code.
There’s speculation about the reasoning behind Google’s motivation for making this change now. Many analysts think that the ongoing legal battle over Java API patents between Oracle and Google is a major driver behind this decision, but all Google would tell VentureBeat is that they are just now warming to the OpenJDK’s recent lineup of features with Java 8’s lambda’s as an example.
Google has already contributed to the OpenJDK in the past, and they plan to make more contributions in the future as they transition fully to OpenJDK within Android. The effect of this change on the Java community could be significant, since many more developers will be familiar with Android’s libraries. The OpenJDK is much more familiar to the wider Java community than Google’s Harmony-based libraries.
Read Shai Almog's blog post for more thoughts on what this means for Android and Java.