Is the iPad a revolution?

"Apple and four major publishers have offered to allow retailers such as Amazon to sell e-books at a discount for two years in a bid to end an EU antitrust investigation and stave off possible fines, a person familiar with the matter said on Friday."

It's still not clear at this point how this will end up and the article is a bit fuzzy. But what's at stake is interesting: will ebooks be sold under an agency model (where publishers set the price and retailers such as Apple or Amazon take a pre-defined cut) or under a wholesale model (where publishers charge retailers what they want and retailers decide which margin - if any - they want to take; a model some say Amazon used to dominate the market with very small margins)?

I've seen the Music industry hesitate between both models and I'm still unsure which is good in the long run. Some can argue Amazon is using the wholesale model to become monopolistic but if you look at Apple and music, you can also see that the agency model certainly didn't prevent them from gaining huge market share.

So is this really a model issue or a network effect coming from the success of a platform model?