Those of you that would like to see some hard numbers in terms of growth should check out this Feedburner report: Podcasting on the Rise
Some notable quotes:
It took us nine weeks to manage our first thousand podcasts, and we added our most recent thousand podcasts in under a month. As you can see, the rate of growth changes in bursts. We added about 800 podcasts per month initially, then 1000 a month, and now we’re adding about 1400 a month.
Just as interesting, podcasts managed by FeedBurner have an average of 33 subscribers, up from an average of 15 subscribers in February. If you discount the feeds with less than 5 subscribers, the average number of subscribers per podcast is 65.
In February, we managed 20 podcasts with over 100 subscribers and hundreds of podcasts with more than 10 subscribers. Now we manage about 20 podcasts with over 1000 subscribers and hundreds of podcasts with more than 100 subscribers.
Just wait until iTunes integrates podcatching.