Edit and save Motion project with fonts.
Open Motion project in Compressor > send to render.
In FCPS 2 fonts were missing always but maybe it has been improved.
It would be really powerfull option if it would work like this.
From time to time i have jobs where you have multiple versions of one
animation. Usually i make PSD versions of animations where all layers are
bitmap. In the other hand it would be so much more flexible with compressor rendering and fonts
from Motion projects.