According to the International Data Corporation (IDC) “Worldwide Quarterly Media Tablet and eReader Tracker” (http://www.idc.com), 10.1 million media tablets were shipped in the fourth quarter of 2010 (4Q10) — more than double the 4.5 million shipped in the third quarter.

Apple’s share came down from 93% in 3Q10 to 73% in 4Q10, but still reflected Apple’s strong leadership position. Samsung’s Galaxy Tab was the primary competitor in the holiday season, beating other players to market and capturing more than 17% share, while a number of smaller regional players also participated.

“Strong holiday sales of media tablets were in line with IDC projections and strong consumer interest in the category while device vendors scrambled to offer products competitive with Apple’s iPad and now iPad 2,” says Loren Loverde, vice president, Consumer Device Trackers. “Media Tablets are on pace to reach shipments of roughly 50 million units in 2011.”

According to IDC, media tablets are tablet form factor devices with color displays larger than five inches and smaller than 14 inches, running lightweight operating systems (such as Apple’s iOS and Google’s Android OS) and can be based on either x86 or ARM processors. By contrast, tablet computers, by IDC’s definition (and I beg to differ) run full computer operating systems and are based on x86 processors.

Media tablets support multiple connectivity technologies and a broad range of applications, which differentiates them from single purpose–focused devices such as eReaders. Media tablet market evolution will be driven not only by product introductions from computer, consumer electronics, and mobile phone vendors, but also by expanded distribution channels (with mobile operators playing a key role) and commercial adoption by businesses, says Loverde.

He says Apple is building on its strong 2010 first-generation iPad launch with the iPad 2, which will ship on Friday, before most competitors come to market with first generation media tablets. Although more competing devices will be launched this year, IDC expects Apple to maintain a 70-80% share of the market.

Samsung started shipping its 7-inch Galaxy Tab media tablet in 4Q10. Although its shipments into the channel were fairly aggressive, a lack of competitive pricing and ongoing competition from Apple stifled consumer demand. Samsung is expected to follow with a 10.1-inch Galaxy Tab with Android 3.0 Honeycomb later this year, but the refresh will have a tough time maintaining share as more competitors enter the market, says IDC.

The recently launched Motorola Xoom is a worthy competitor in function, although the relatively high price is expected to be a barrier to gaining significant share, according to the research group. Lots of other vendors and designs are expected to hit the market in earnest in the second half of 2011.

— Dennis Sellers