As of StepMania 3.9 alpha 5, the answer is yes. To use this feature, copy the file "statistics.ini" file from the StepMania 3.0 final directory (usually C:\Program Files\StepMania) to the StepMania 3.9 directory (usually C:\Program Files\StepMania CVS).
* Be sure that you have copied all of your songs over from SM 3.0 final or else some scores will fail to import.
* When copying songs from 3.0 to 3.9, do not rename any
song folders. For example, if have a song in StepMania 3.0 at "Songs\4th
Mix\B4U", the song must exist in SM 3.9 at "Songs\4th Mix\B4U". If these
names do not match exactly, scores will fail to import.
Some notes courtesy of Aaron VonderHaar:
You can get the libmad RPM for RedHat 9 here.