What other nice 'extras' would help you along your journey to podcasting fame? Pop filters, for one. They remove the annoying voiced p's and b's that often spoil the flow of a recording. Extra bonus: it protects your shiny, expensive mic from saliva.
A mixer, wires, a nice soundproof studio - all these help your podcast sound more polished. But when you're just starting out, best not to go crazy with the gear. Build up a following, upskill your audio editing-fu and build a solid podcast subscriber base on iTunes before you blow good money on gadgets.
There is no point creating super-polished audio if the content isn't worth listening to in the first place. When it comes to podcasts, one of the most important tools is the stuff between your ears. Creating good content for listeners to keep coming back for is the hardest part.
Make the most of whatever gear you can afford starting out, have fun and hear you on iTunes!