> This claim is frequently repeated, but does not reflect reality for those who buy Apple devices. When iPads actually meet user needs, the result is iPad proliferation, not replacement of MacBooks

Of course more versatile tablets will replace laptops/notebooks, the only reason the latter are preferred over the former is because they offer features which the former do not yet have. Add those features - which mostly comes down to removing restrictions - and there will be far less need for ultralight notebooks. Add the features to (i.e. remove restrictions from) large-screen tablets and laptops will be far less necessary. Even people with more money than sense will see the utility in having only one device which they need to keep charged and for which they need to get a mobile data subscription.

An uncrippled modern tablet with a good keyboard/cover is a good replacement for many if not most common tasks notebooks are used for. A larger uncrippled tablet with such a cover is a good replacement for many tasks laptops are used for. Not for all tasks, not yet. That time will come as well but we're not there yet due to battery capacity restrictions and thermal limits but it will come. The market went from fridge-sized desk-side to tower to desktop to 'luggable' to portable to laptop to notebook, the next step is either a tablet of some sort or some form of wearable. If and when some form of direct interaction without need for a keyboard and monitor ever comes to pass for mainstream applications it will be the latter.