My idea would be that at least hardcovers should contain a code or another (smarter) way to allow people to download the book also as ebook.
The idea to be able to download an eBook whenever I want instead of having to go to an obscure pirate site and feeling guilty for being a pirate would make me pay money rather than looking for a pirated free version.
I recently got a Kindle and like it a lot, but what I not like is also what made me hesitate to buy one initially: DRM, and Amazon being anal about their MOBI/AZW format they use instead of EPUB. They do not even allow EPUB and I have to use Calibre to convert books, what a BS.
Still I also see that it takes quite a lot of faith to offer books totally DRM free. Experiments by various authors have shown that sales were not affected negatively, I think it was Paulo Coelho who pirated himself and managed to make his books much more popular in Russia and also sold many more books there than ever before.
I can only speak for myself but I could have pirated all the books I recently bought easily. I didn't. Apparently people who need specialized books that cost quite a lot of money either buy them and accept the price grudgingly or pirate them. Regardless if there is DRM or not. So yeah, I think removing DRM is showing insight that a certain piracy will always exist but that there will also always be honest customers.
And if things really don't work out on a grand scale... welcome back, DRM. It's as easy as that.