I've added some ebuilds for Flightgear 1.9.1 to the Sabayon Overlay.
The master ebuild is games-simulation/flightgear-1.9.1, and it will pull in the added dependencies: dev-games/simgear-1.9.1 and media-libs/openscenegraph-2.7.5.
I've had trouble locating a changelog for the new features since flightgear 1.0, so I'm not sure what's new.
But it's good to see development moving along in this project.
Gigabyte GA-P35-DS3L - Intel(R) Core(TM)2 Duo CPU E6750@ 2.66GHz
nVidia GeForce 7600 GS
2 GB RAM