Sure, microphones and book narrators have been around a long time. But with a $60 microphone, a computer, a bit of egg crate foam, an Internet connection, and a glass of water and we can record--and distribute--our audiobooks ourselves.
I suppose it's partly because I'm proud of my words but there's a part of me that hearing the words spoken, listening to the...
This is where things can get exciting with your book as a podcast as opposed to (or in addition to) an audiobook.
My only concern with using dictation is how my mind, and how my imagination, will adjust to it.