I went to world's largest self-published comic book fair "comic market(Comiket)" at the end of last year.
What comic market ? via Wikipedia
I was able to watch the "change" that was here this time. It is that a lot of creators were using the tablet. iPad, Kindle, galaxy Tab......(and a little PSP, too). There were a lot of people who were using iPad.
In last summer, there were a few people who used tablet. Main users were the people who wrote a novel as the people who made a game. But, I was able to watch tablet with every genre this time. There was even Cosplayer which showed a collection of own Cosplay photographs on iPad.
The e-books correspondence of the publisher in Japan is much later than foreign countries. But Japanese creators begin to make e-books steadily.