But without Agency, it's entirely possible we'd be living in a Kindle-only world.
Amazon was using ebooks as loss-leaders to sell Kindles. $9.99 for the latest bestseller. The publishers hated it because it cannibalized their hardcover sales. But the danger went a lot further then that.
One of the boards I read (I think it might be mobileread.com) introduced me to the concept of a monopsony. Call it the flip side to a monopoly. There existed a very real possibility that Amazon would become the only practical retailer for ebooks, thanks to their willingness to take a loss to build market share (and the deep pockets to enable taking that loss.)
I much prefer the current, varied ecosystem in ebook retailing. I like owning a Kobo Touch, which lets me read ebooks from anybody selling epubs (as long as they don't use customized DRM, but hey, it's a pain getting Barnes & Noble to sell to a Canadian anyways, so who cares.) Amazon wouldn't work nearly as well for me. Canada is an afterthought market for Amazon.
The trial is proving interesting. CNN/Fortune has really good coverage on their Apple blog.