One of the potential values of podcasting is drive-/walk-/run-time access to blog posts. However, a good blogger does not necessarily a good radio voice make. I've been playing with Cepstral's text to speech (tts) synthesis demo and found it to be remarkably good at speaking short blog posts. Here is an mp3 (wav) of a recent post.
This demo is of the Cepstral system with no blog specific mods of any type. Certain structures (in this case parenthetical text) could be dealt with in a slightly more listener friendly manner, but as an out of the box demo, this is really great.
Now imagine being able to listen to posts from your morning read away from the computer. Systems like Cepstral's offer multiple voices, and many configurations providing lots of potential to vary the voice per post, have quoted material spoken in a distinct voice and so on.
Note that speech is another example of an annotation stream!