Yesterday I updated my iPod's firmware in order to see how the podcast support looks like. I uploaded some material with iTunes and it all loked good.
But the podcast support lacks one of my favorite iPod features - variable playback speed - the audio book support has that. The podcasts I listen to are strictly speech and listening to 10-20% faster version is really a blast. So I'll stick with m4b files and drag-and-dropping them onto iPod.