Do 2 Million ABC Podcast downloads = "mainstream (or "opportunity")?

An article in The Age recently makes the case 2007 was the year that podcasting hit the mainstream, citing download numbers from ABC and other radio stations. 

"The ABC is now regularly topping two million podcast downloads a month. Austereo (owner of Triple M and Melbourne's Fox FM) is registering more than 850,000 a month across all its stations, a figure that is increasing by 50,000 each month."

It is definitely great to see this sort of growth and definitely more and more people are becoming aware of the opportunity presented from podcasts. However, I would argue that podcasting is a long way from main stream.  Try asking someone on the street what a podcast is. You will get either strange looks looks or lots of different answers.  Try suggesting to someone over the age of 40 that they should listen to a podcast. Most will respond, "I don't have an iPod."

The number of downloads is one metric to measure podcast interest. Another is the number of people doing a Google search for podcasts (shown below). You will note that the trend has been pretty level for the past 2 years.

I agree that there is enormous opportunity in syndicated digital content (I hate the word podcasting for the reason illustrated above).  And, podcasting continues to make gains. But there is a lot left to be done before it is a truly "mainstream" media or where it can replace any sort of traditional media.