Then they need to do something like what Samsung did for the Tab Pro tablet:
http://www.samsung.com/us/mobile/galaxy-tab-accessories/EJ-CT800UAEGUJ
This effectively turns the 10.5" tab pro into a laptop.
Apple has to start actually thinking about what it means to be "productive" and not just assume people want a larger tablet = productivity. Relying on 3rd parties to add the features to increase iPad productivity will result in a mishmash of disjoint add-ons that will cripple iPad's mobility in lieu of Apple simply not designing proper productivity accessories for the iPad.
The fact Apple has not created their own keyboard/case for the iPad speaks volumes of how far off Apple is in terms of understanding what it means to bring productivity to a tablet.