Not necessarily, though their popularity is certainly catching on. As of August 2005, a Paragon Media Strategies survey showed that 51% of those who responded indicated they still listened to music primarily on the radio and only 3% showed they downloaded music by way of pod or vodcasting.
The pro of a downloaded podcast or vodcast is that it can be played, replayed, and archived just as any other computer file one might download. In addition to this, there are major benefits to both publishers of pod and vodcasts as well as the subscribers. The publishers are able to "bundle" content for their audience and the subscribers are able to consume the content when they want and don't require the use of either a keyboard or a mouse to choose what they hear and/or see. This is akin to flipping the channels on a television with the touch of a remote, and new programs automatically appear, making the consumption all the more easier for the subscriber.