I second the request for bookmarks in podcasts. At very least a way to mark where I left off would cover the most basic needs. I don't often annotate podcasts, but I could see that being very powerful too.

I'd really like to see a "shortcut" plugin that I configure with icons to take me straight from the main screen (or a "shortcuts" screen one screen deep) to my favorite activities. In my case that would be browsing album covers and perhaps a few favorite streaming radio stations or podcasts. The big motivation here is to avoid having to scroll through the text lists because there are times (e.g. driving in the car) when navigating those lists of text is nearly impossible. Main screen shortcuts are not the only way to do this--you could iconize the existing text lists for example--but I think think the ability to jump right to your favorite activities and bypass the intervening 3, 4, 5, or more screen taps would be really great too.