Google has closed down access to Android 3.0, AKA Honeycomb, and the world seems to be up in arms about it. There are cries of "I told you so" and "Just as bad as Apple" ...
This isn't how open source is supposed to work but then again Android isn't really open source. It is very much driven by what Google wants to do with it rather than any sort of community development process. Google has stated that the source code for 3.0 will not be made available until it has settled down and will work on a range of devices. Apparently Google doesn't want the code being ported to phones and providing the user with a less than good experience.
Google has restricted access to source code before just after a new release so this isn't the first time this type of "unauthoerised" use has been controlled. Of course Google is a little late in closing the doors as xda-developers have already ported Android 3.0 to a phone and discovered the Google music service in the process.
The real reason for Google not open sourcing the code for Honeycomb is probably its desire to restict which hardware manufacturers make tablets using it. A large number of Chinese manufacturers have already created low cost Android 1.1 and 2.x tablets and a low cost 3.0 tablet would take the edge of any manufacturer tying to launch an up-market iPad killer based on Honeycomb.
Android can't really be a 100% open platform even if the code was to be 100% open source. The reason is simply that phone companies sell you phones at a discount and make up the difference in call charges. To make this work the phone and the software have to be locked down to their services. If you are happy spending the extra you can have an open phone and then there really does seem to be little excuse for not having a 100% open system - apart from some commercial interests that is.
Even so you do need to consider what the importance of an open source operating system really is. How many Android applications programmers look at the Android code? A small hardcore of systems programmers want to port Android to new hardware and yes it is nice to know that you can get an upgrade for your hardware without involving the mostly incompetent phone providers. But the fact of the matter is that if the source code for Android was locked away in a safe for ever the environment would still be more open than either Windows Phone 7 or the iOS, which are not only closed from the point of view of the operating system source code but from the point of view of running apps on the platform.