Since the licensing terms for mp3 technology has been the same for almost two years now, I assume the empeg guys already paid the fee,
so - in theory - nothing has changed.

Looking at this http://www.mp3licensing.com/licensees/index.asp it looks like sonicblue has paid; And I;m pretty sure that covers the empeg/riocar ....

Nothing to worry about.
And OGG is working quite stable,
only the quality is still slightly below mp3....