Not in the current implementation.
DRM is an evil in the software would that will eventually go away.
People are beginning to realise that business practices that have worked for the past century just won't work when things become easy to copy. It reduces their value, almost to zero. This goes for books, films and music. Anything that may be considered some form of what some people call 'intellectual property' (I dislike the term).
For books that are copyright-free, there's already the gutenberg project website, which will work on eReaders such as Sony's.
Mark Pilgrim has an excellent explanation for why the current implementation won't work:
http://diveintomark.org/archives/2007/11/19/th e-future-of-reading
The technology to do the things you say won't work. Think about it -- why should it be like that? Imagine you're a slow reader and only get half way through the book before it gets automatically deleted. This isn't acceptable.
The idea is great. But apart from the technical limitations (you want a roughly 200dpi screen with sub-pixel aliasing; the iPhone has one of the best right now, at 160dpi), the concepts that book publishers are trying to enforce will stop any real progress being made.