"Most people are going to have a notebook and smartphone and in the middle there will be for or five categories of devices and each category will have different attractions for different people," said O'Donnell.
Only 1.1 million PC tablets targeting business users shipped last year. New tablet devices like the Apple iPad have an improved user experience and are aimed at consumers. O'Donnell called them a wild card and said Apple alone could sell four million tablets this year.
Despite the fact the iPad includes an e-book reader, many people will prefer dedicated devices using E-Ink displays rather than the LCDs on consumer tablets. "I don't care whose LCD it is, it's a lamp and people don't want to stare into lamps," he quipped.
Mo bile Internet devices are the big losers in IDC's view because they have relatively small 4-7-inch screens, yet are expensive. "This is a category in search of a need," he said.
On the other hand netbooks, also called mini-notebooks, are a clear winner. Now that the products have evolved from 7-inch displays and Linux to 10-inch displays using Windows the category has taken off, shipping 34 million units last year and rising to more than 45 million in 2011, IDC predicts.
Good synchronization technology will be a factor that determines winners in mobile devices, O'Donnell said. He called for a portable universal ID technology that would let users easily access any personal content or service on any device.
"None of these devices will be successful if they are an island," he said. "The only way the world of multi-device ownership works is when you have an ability to synch across devices, so this will separate the men form the boys," he added.
Meanwhile a new kind of eco-system is developing for mobile devices, led by Apple and based on simpler applications. "We need to rethink what the software is, how it runs and is paid for," he said.
Another key piece of the puzzle will be data service plans that allow users to have multiple devices. Telcos hungry to raise their revenues won't offer such plans for some time, but users will demand them, he said.
There no way people are going to go for single-device data plans--one data plan, multiple devices is what people want," he said.