Is there any interest in just getting GTK+ (or X if you want to go lower level) working on top of SurfaceFlinger surfaces and arrange for the appropriate libraries to be built in an NDK-compatible way so one could port existing apps such that they'd run on any Android system from Gingerbread forward (which is quite a lot of devices in the field)?
I may be misunderstanding the goals, but it would seem like there are simpler paths to getting existing Linux apps running on Android than replacing big chunks of platform internals...