Google, via the Android Developers Blog, issued a statement a short while back. Here it is ...
A Note on Google Apps for Android
Posted by Dan Morrill on 25 September 2009 at 2:31 PM
Lately we've been busy bees in Mountain View, as you can see from the recent release of Android 1.6 to the open-source tree, not to mention some devices we're working on with partners that we think you'll really like. Of course, the community isn't sitting around either, and we've been seeing some really cool and impressive things, such as the custom Android builds that are popular with many enthusiasts. Recently there's been some discussion about an exchange we had with the developer of one of those builds, and I've noticed some confusion around what is and isn't part of Android's open source code. I want to take a few moments to clear up some of those misconceptions, and explain how Google's apps for Android fit in.
Everyone knows that mobile is a big deal, but for a long time it was hard to be a mobile app developer. Competing interests and the slow pace of platform innovation made it hard to create innovative apps. For our part, Google offers a lot of services — such as Google Search, Google Maps, and so on — and we found delivering those services to users' phones to be a very frustrating experience. But we also found that we weren't alone, so we formed the Open Handset Alliance, a group of like-minded partners, and created Android to be the platform that we all wished we had. To encourage broad adoption, we arranged for Android to be open-source. Google also created and operates Android Market as a service for developers to distribute their apps to Android users. In other words, we created Android because the industry needed an injection of openness. Today, we're thrilled to see all the enthusiasm that developers, users, and others in the mobile industry have shown toward Android.
With a high-quality open platform in hand, we then returned to our goal of making our services available on users' phones. That's why we developed Android apps for many of our services like YouTube, Gmail, Google Voice, and so on. These apps are Google's way of benefiting from Android in the same way that any other developer can, but the apps are not part of the Android platform itself. We make some of these apps available to users of any Android-powered device via Android Market, and others are pre-installed on some phones through business deals. Either way, these apps aren't open source, and that's why they aren't included in the Android source code repository. Unauthorized distribution of this software harms us just like it would any other business, even if it's done with the best of intentions.
I hope that clears up some of the confusion around Google's apps for Android. We always love seeing novel uses of Android, including custom Android builds from developers who see a need. I look forward to seeing what comes next!