I'd love to maintain the same rights with ebooks as I have with pbooks, but realistically it just ain't going to happen. Think of it this way.

Once upon a time, books were copied by scribes. Copyright wasn't necessary since copying a book was so expensive that it was rarely done.

Then came the printing press. All of a sudden, copying became easier. Anyone with a printing press and enough incentive to setup the press for a particular book could make a large number of copies. The notion of copyright eventually takes hold. Few people have to worry about it though since it's easy enough to track down and prosecute the owners of a press.

Over time the setup process became much easier and presses became more prolific. Eventually we would end up with devices like photocopiers, and they were everywhere. Readers started worrying about copyright, but not too much because enforcement wasn't a huge issue. Anyone with a big enough press and distribution channels were easy enough to track down, everyone else didn't matter.

Ebooks are the next step in that progression, and it is quite an astounding one. By their very nature, computers copy prolifically. The act of reading a book involves making many copies: from the main storage to RAM (in a more-or-less complete form) to the registers of the CPU (very fragmented) to the video memory (usually rasterized, but sometimes not). Now imagine transferring that book to someone else. We may talk about a "file transfer", but it is actually copying data across a wire. The only way to actually transfer the file is to add additional software that destroys the original data after it is used (which is what the move command does in your file manager). Factor in piracy, and we are clearly working in a very different realm than the pbook. Because of that, copyright is going to have to change.