I don't know about the "wholesale cost for a new ebook is around $10", as someone put it. The retail price of a typical Kindle ebook is $9.99, so the wholesale cost would be less.
There are already a lot of ebooks available for reading online at
www.wowio.com, for example. I pay money for access to Safari Online, another source of current book-clouds of a sort.
I'm all for having my books in a cloud, but there need to be quite a few clouds, not just one controlled by one group. Big companies are good for some purposes; they can do battle with big countries, if they are willing to. Big companies HAVE to do battle with other big entities in order to survive, that's why Microsoft is in court a lot, and most big companies are also. Because they are multinational and subject to the laws of all the countries they operate in, multinationals are independent of nations to a certain extent, something that is good in some ways and bad in others.
Just some thoughts...