I was on the phone late last night with a person that attended Podcamp NYC and she said one of the take always she had was that in a session lead by a podcast consultant that said updating ones show at a minimum once a month is ok.
Quite honestly if you want a audience of a 100 people that is good advice, but if you plan on building a real audience do not for a second think that producing a single podcast a month is enough.
This brings me to a couple of points, when someone is saying they are a Podcast expert you better check out what they have really done in the space beyond talk, and promote themselves. Their are a couple of other things I have been seeing in the space that are disturbing as well.
If you are going to be attending a podcast training event where you spend big dollars to get told the magical formula of podcasting I can save you a lot of money with five words.
Content, Passion, Consistency, Branding, Exposure
If you have all 5 you will have a great show and a great audience regardless of what snake oil someone is selling. I liken some of the things that have been happening in the space recently to that of a Multi-Level Marketing scheme.