Well I've just found an interesting and useful usability addition to the new iPod Touch OS for podcasts.
One thing I liked about my old iPod Mini over the Touch when I purchased it was moving through podcasts. As the Mini had the scroll wheel you could move through slowly or quickly depending on how fast you scrolled. The flat bar of the Touch meant the smallest increment was often too much, especially as some of the podcasts I enjoy push two hours. The new 3.0 OS upgrade has addressed this and I haven't seen this specific thing announced anywhere else. When moving through a podcast manually, if you drag your finger down the movement increment is reduced. Allowing to quickly and easiy place the play point where you want to.
A nice little usability touch that makes life a lot easier. Though why Apple didn't advertise this I don't know. They really need just a full size super long patch notes that people can browse.