In iPhone OS 2.x, we bemoaned the seemingly useless nature of the repeat and buttons when it came to podcast playback. They just sort of hung around, like guests who were welcome when the music was playing, but just wouldn't leave when the party was over.
Now, in iPhone 3.0, Apple has replaced them with an email icon on the left hand side, and a speed counter on the right hand side. The email icon supposedly allows you to send an iTunes Link for the podcast (similar to how you could previously email YouTube video links).