Android isn\'t open source, what now\?

So Google's admitted that Android is not open source. Some parts are, some parts are not. That's the same with iOS. Many parts of iOS are from open source projects (I'll mention cups, the printer stack on many Linux systems, that is very much supported by Apple, even though it's GPL). Heck, even Microsoft Windows has components from open source projects (the ftp client being my favourite example). To me, it's not so much about these projects being open source, as what do they give back to the open source projects.

The kernel and userland of both OS X and iOS is based on various BSD systems, I believe for the most part FreeBSD, and put into their own BSD system called Darwin. Darwin is open source and under the BSD license. Now, I'm sure Apple makes many changes that are so specific for their use and their scenarios that you don't necessarily want these changes committed back as they may be a diversion from the project rather than something that's good for the project. However, I'm sure they make great improvements to the OS, and for me the real benchmark of their openness is how fast these changes flow back to the originating changes and thus become a benefit for all parts. Unlike cups which is under GPL, Apple isn't required to send this code back. I don't mind that at all, but I still hold that my benchmark for their openness is how much useful code they volunteer back to the originating project.

I'd love to hear how many changes made by the Android development have benefitted the originating open source projects. I have an idea about how much Apple has committed back to the FreeBSD project, but I don't have any solid facts at the moment, so if anyone does, that'd be great to hear. Hey, even hearing how much Microsoft's mobile offering has led to improved code being committed back to open source projects not originating at Microsoft would be great hearing about. I'm looking forward to reading your comments