For years, pundits have been predicting that e-textbooks will take the education world by storm, but so far, adoption has been slow. According to one analyst, digital textbooks accounted for only 3 percent of the textbook market at the end of 2011. But all that may be changing, as Apple announced its entry into the market with the new, free iBooks 2. In its first three days, the app delivered more than 350,000 copies of e-textbooks to users. Will Apple's golden touch tip the scales in favor of e-textbooks?