My reason for making global predictions is as follows:
Everyone wants to get connected today. On every continent, in every culture, rich or poor, they all want to connect with information and people.
Right now phones are serving this function to a greater or lesser degree, and they sell about 1/3 of a billion phones every year. So let's not talk about small markets here, or talk about what is needed versus what is wanted. There is no need to sell 1/3 of a billion phones every year, for you can just use the one you already have. Yet the phones sell.
Every year there are many millions of PCs sold throughout the world. This too continues despite there being "no need."
The iPad is so inviting to use, and covers 90% of PC functionality, that most people will prefer one to a traditional PC. Many of those phone users will enjoy having a larger screen to view information and play games. This is a huge market.