Hi, I'm working on a project called gentroid. The goal of the Project is to port art (dalvik successor) and the android framework to gentoo. I created an overlay (https://code.google.com/p/gentroid-overlay) for the android libraries and tools and their dependencies. Because the android repositories probably exceeds the limits of my google account, I'm working with a private git-server. So I only upload the patches (mostly cmake files) on https://code.google.com/p/gentroid and the gentroid.eclass puts the source code together again. The project is under heavy development and I'm currently trying to port the android graphic stack to wayland. This is just for your information, but maybe you find some useful ebuilds in my overlay.
Simon