One of the major hassles of subscribing to podcasts and listening to them is the anonymity level as far as the content goes. Even though it might give an element of surprise incase the podcast turns out to be good, in most cases, the listener would want to know what’s its all about, whether he can listen to selective pieces of podcast.
Here’s Eric Gwinn airing the same opinion as mine in NYT

Podcasts should reel in a brief table of contents

I’m listening to more podcasts than ever. If you make them or listen to them, please help me in my quest to get one thing standardized: a table of contents. It isn’t hard to make. After the podcast has been recorded and before it has been made available for download, the podcaster could record a couple of seconds saying, “At 2 minutes and 31 seconds, I start griping about the latest stupidity in the mainstream media. At 5 minutes and 19 seconds, I answer the question, `Why do cartoon characters wear clothes?' At 19 minutes, I talk about. . . . "

Many good podcasts make such program notes on their Web sites, but many listeners aren’t logged on when they’re checking out the podcast. For them, a table of contents would help.

It could be pasted at the introduction to help listeners use their MP3 players to scan to the next topic if they just want to skim now and listen in depth later.

What if the there is some techy thing which helps the podcaster automatically come up with a TOC ? hey, may be its a nice piece of software that can be built over a weekend!