IDC figures suggest that Android shipments should overtake those of iPads in 2013, although that's a slightly different thing from actual tablet sales.
The IDC figures cited by AllThingsD suggest that Apple's tablet market dominance will end in 2013, with Android tablets set to take 48.8 per cent of the global tablet shipping market to iOS' 46 per cent. Windows is said to take 2.8 per cent, Windows RT 1.9 per cent and the remaining 0.6 per cent goes to other platforms. By 2017, it's suggested that Android will still be in front 46 per cent to iOS' 43.5 per cent.
However, as the report notes, that's based on shipping volume, not final sales, and that's something that Apple is rather good at, given it manages its shipping to the very finest degree — or in other words, the vast majority of iPads shipped are also iPads sold, whereas some Android tablets simply ship and sit in warehouses or on store shelves.
Will This Be The Year Android Topples Apple in Tablet Market? [AllThingsD]