If anyone is interested, I've written ebuilds for a fair number of the ROS
packages.  At my day job, we've been using the electric packages for a couple
of months now without any major issues, and the cturtle ones were also
stable.

Note that I did do a fair bit of patching for things like using system
libraries, respecting user compile flags and handling library upgrades.
This might be helpful to some of the package maintainers.

I can't make any guarantees that I'll be closely monitoring ROS development
and updating the overlay when required, but I will do my best to respond to
any patches or pull requests.  Hopefully this will aid in making ROS a bit
easier to use on Gentoo.

Enjoy, https://github.com/jsbronder/overlay-ros

-- 
Justin Bronder