I think this debate is really just the ebook bit of a far wider change in the way we consume and distribute digital media and assets. First off I put may hands up to working in the internet industries and having more than a passing interest/involvement in the digital media industry.
Now to my point. We are seeing, in all digital media fields, a change in the way songs/films/books et al are being consumed. I look the younger members of my own family (nephews and nieces from 7 to 21) and see them using very different ways of choosing what they buy.
Simple example, my nephew wants to see a particular film. He has already defined in his own mind what he is prepared to pay to see the film and then looks for a supplier. That could be a traditional internet side or via his xbox or maybe his Archos Media Player. If he believes the price is too expensive he just looks for another supplier.
I think this is the fundimental change, where with CD, DVD and even books, we were in the past forced to buy at a given price (remember when every CD in the UK was at least £12-99), todays internet generation (i.e. the ones who have grown up with an internet being there) are using different consumer rules. The internet isn't just free content but it has to have content that is priced correctly.
Someone earlier said if a DRM'd book was $2.99 they wouldn't mind but if it was $15.99 they won't consider purchasing. This for me is the essence of the new digital market. If I can "rent" my DRM'd ebook at a reasonable rental price, re-read it as I want on my device but then 'rent' a new copy for a new device I have much less of a problem with DRM. That said this means that DRM should be priced at a fraction of the cost of say a printed version, and most ebooks are more expensive in my experience.
That's my 2 cents worth
