Your management of podcasts beats anything on the market, even ipod.
This issue is the clear bookmarking of where you left off. Ipod do it, but if often forgets and does not show you before your load.
Book marking is so important because many podcasts are long and you can'nt listen in one siting.
A cool similar marget is audio book play back - which your product is nearly perfect of as well. A "pod cast and audio book manager player"
If you search for audio book play back and blackberry you will see many people looking for a auto-bookmarking mp3 players - like ipods do. none really exist. The best required to "save" the position before you quit.
The blackberry native music player is great to music, but makes no effort to manager long audio books.
Food for your product.