As you may know, Matt Porter was heavily involved in the MIPS and PPC ports of Android, so he and his team have seen the lowest levels of Android, more and deeper than even cellphone manufacturers ever have to look into it.
The slides of his presentation are now available for download. I would personally recommend this as mandatory reading material for everyone who has some interest in Android.
The presentation explains in detail why Android is not what most people refer to when they say Linux. What most people mean when they say Linux is the GNU/Linux system with it's standard userspace tools, not only the kernel.
The presentation shows how Google has simply thrown 5-10 years of Linux userspace evolution into the trashcan and re-implemented it partially for no reason. Things like hard-coded device lists/permissions in object code rather than config files, the lack of support for hot-plugging devices (udev), the lack of kernel headers. A libc that throws away System V IPC that every unix/Linux software developer takes for granted. The lack of complete POSIX threads. I could continue this list, but hey, you should read those slides. now!
Just one more practical example: You cannot even plug a USB drive to an android system, since /dev/sd* is not an expected device name in their hardcoded hotplug management.
Executive summary: Android is a screwed, hard-coded, non-portable abomination.
I can't wait until somebody rips it apart and replaces the system layer with a standard GNU/Linux distribution with Dalvik and some Android API simulation layer on top. To me, that seems the only way to thoroughly fix the problem...