I was going to write a long and involved post on the Macmillan/ Amazon issue. But instead, I'll point you at this articulate, balanced, and detailed post by Tobias Buckell. It is long, but well worth reading, and I agree with his analysis and conclusions.
ETA: If Buckell's site is still having hosting problems, you can read his post on the SFWA site as well.
If you are still interested in my personal feelings here they are:
I don't, as yet, have an e-reader. I can see situations where I would want one (like over Christmas, where there was a pug in one of my carry-on bags, and a laptop in the other - it would have been nice to be able to pack a device, rather than an assortment of paperbacks), but I prefer to read paper books. Having said that, if I did have an e-reader, the price point of e-books would simply be one other data point that I would take into consideration when deciding when, and in what format to buy a book.
When I buy a book, unless it is a rare or limited edition, I am buying it for the content, not the delivery medium. Some authors I buy in hard cover, the first day the book is available, some I wait until the mass market paperback edition. I balance the cost of the book with my impatience to read it. Having an e-reader would just mean one more data point to consider when I decided when to buy the book.
But that's a decision I am quite capable of making on my own. I really don't appreciate Amazon behaving like the class bully (and, sorry Amazon, but that, and not a consumer advocate, is what you look like right now) and injuring the people who work for or publish with Macmillan because it thinks that I am too stupid to decide how much I am willing to pay for something.