One very important thing that's missing from the discussion is :
Where does the piracy becomes a major problem?
If we open any survey, it'll rank China as a N1 world pirate, Eastern Europe/ex USSR republics and India next.
Why do those countries lead in piracy? It's simple, because residents have low income, some places as low as $200-$300. Yet, compared to US for example, most of the goods have higher prices (oil, cars, electronics, clothes, etc). So how do people there survive? They use intelligence property at all levels for free, including ebooks.
There's no chance people in 3rd world countries will pay $10 for a book.
So generally - Yes, there are places that piracy in general and ebook piracy in specific will be on the rise for the next few decades...