But IDC also argued that the iPad has legs the rival tablets do not. "Apple's move to position the iPad as an all-purpose tablet, instead of just a content consumption device, is resonating with consumers as well as educational and commercial buyers," Tom Mainelli, IDC's research director for mobile connected devices, said in a statement earlier today.

According to Mainelli -- and O'Donnell echoed his colleague -- Apple's positioning of the iPad as more than a consumer product, one appropriate and salable to major markets like education and enterprise, sets it apart from the competition.

Apple has regularly beaten that drum. Last month, Apple's chief financial officer touted a 10,000-iPad deal with the San Diego School District, and said the district planned to buy another 15,000 iPads in the second quarter.

In the same April earnings call with Wall Street analysts, Apple CEO Tim Cook called iPad sales to businesses "off the charts."

"But it's too early to say that the battle is over and done with," cautioned O'Donnell, referring to Apple's current dominance of the tablet market. "That would be an incorrect assumption."