From author and former agent Nathan Bransford:
I say no. We’re not in a [self-publishing] bubble. This is not a temporary blip.
There are sooo many people who are writing books out there. There even more who want to write a book and believe they have a book in them. There are thousands upon thousands of unpublished manuscripts out there and even more in progress.
And it’s not new. People have been writing books for years.
Blogging was a blip. Books are far more central to our culture and are far, far more glamorized than blogs. Lots of people want to grow up and be a famous author. Fewer want to be a famous blogger.
And the ease of entry into the self-publishing game is only getting smoother. Right now it’s still somewhat challenging to make your book available in all channels, but those barriers are coming down. There is a massive supply of books in the pipeline.
Get used to the self-publishing boom. We’re just getting started.
Link to the rest at Nathan Bransford