Seiously guy, go away. I'm so tired of hearing this. Android is open, Google apps are not. You can download the source for Android right now, modify it freely, and put it on a device. It may not be as open as some Linux distros, in that not everyone can submit code that will make it in to the official distro, but it is still open.
I don't see any problem with saying that Android is not an open system. They use open source, but the way it is distributed takes away many of the freedoms of OSS. Also, most of the system is really in the Apps, many of which are closed source. In other words, Android is as much open source as the iOS is, because it is based on an open source kernel but the user space is full of non-open components. And good luck trying to contribute something back to the owners of the system...
Eh, releases are arbitrary points in the development cycle. There is new, stable, stuff in the dev trunk today, we just don't get to see it.
I don't see any difference between Google code-dumping (because that's all they do) "releases" of Android and iD Software open-sourcing old versions of idTech. iD is just more honest about it.
If you remove the community-based aspect from open source, there is not much of an advantage in it. This idea of regular code-drops seem just like a way of maintaining the minimum requirements to conform to the open source tag.
If you'll look at a few recent commits in the Android code-review system, you'll see quite a few non-Google email addresses: https://android-review.googlesource.com/
Right now, you can install applications distributed by non-authorized third parties onto many Android systems, and you cannot do so on any iOS system without jailbreaking. There are many other important meanings of "open" which Android may or may not satisfy, but those aren't what's being discussed here.
