maciej ceglowski has put up a manifesto that is definitely worth reading there.

But before you jump on the audioblogging bandwagon, remember this - the power of the Web is the power to choose. You make your own trails, and
your own links. You read what you like and skip the boring bits. And audioblogging takes that power of choice away. Your listeners become a passive audience - they have no power to skim, they can't skip the boring parts, they can't link or excerpt your post effectively. Your post becomes invisible to Google and other search engines. And anyone who has a hearing problem, or a dialup account, or doesn't speak your language too well, anyone who is trying to surf your site from the office, or from an Internet cafe - well, they're just plain out of luck.