I thought you'd like a sneak peek on a new feature that I just pushed to the master branch. It's a new "MeshStyle" called "DistanceFieldStyle", and its main use is smooth rendering of bitmap fonts of any scale. It also supports some special effects (outline, glow, drop shadow) that are rendered right away, i.e. without detours over filters or render textures!
The style requires that you process your textures with a certain "signed distance field" algorithm, but there are several tools available that help with that.
I started writing the documentation of this feature in this wiki article; refer to that for more information! -> http://wiki.starling-framework.org/manual/distance_field_fonts
I think that's a great addition for the Starling toolbox -- I hope you like it!