“The iPad Is Shaping Up to Be the Tickle Me Elmo of the 2010 Holiday Season.”

So says iSuppli, which today raised its calendar 2010 forecast for iPad sales to 12.9 million units from 7.1 million. The market research outfit expects Apple (AAPL) to sell 36.5 million iPads in 2011, and 50.4 million in 2012. It’s also looking for a hardware refresh in April of 2011, one that will include the introduction of an internal camera and presumably a built-in voice box that enables it to shout, “You tickled iPad! Again! Again!”

The trick for Apple will be to avoid the kind of supply/demand imbalance that caused so much unpleasantness at the height of Elmo-mania. Customer fistfights in the aisles of the Apple stores would be unseemly.