iSuppli is forecasting that Apple will maintain its lead in sales of tablets for a couple of years thanks to an early start and tight supplies of components. Apple has made huge purchases of parts in advance and still could not meet demand so competitors are struggling. That difficulty should end in 2011 and tablets running Android will see dramatic growth.
For tablets, iSuppli predicts nearly 59 million will ship in 2011 with iOS on 2/3 of those. The shortage in supplies means prices will likely stay high until the end of 2011. Then the floodgates will open with shipments expected to double in 2012 and Apple losing share rapidly.