IDC reports that the global tablet market grew 142% YOY in the first quarter. Tablet makers shipped 49.2 million devices the same quarter. Apple shipped 19.5 million iPads giving it 39.6% of the quarter's market share. Though Apple experienced unit growth iOS its share declined from 58.1% to 39.6%. Android is now the dominant tablet OS worldwide.
There's no denying Apple's contribution to popularizing new device form factors like the tablet but a standardized CPU and a global ecosystem of manufacturers will overtake a monolithic vertically integrated (proprietary hardware & software company) over time. Already the ARM-Android ecosystem is overtaking the standalone ARM-IOS one, but even this one will be overtaken by the Intel x86 ecosystem that gives vendors scale and consumers the advantage of being able to run Windows, Android, Tizen and any other flavor of *nix that comes along.