If you boil the iPhone down to it’s essence, it’s value proposition is being a constant connection to the internet. Permanently attaching a screen size to it causes unnecessary anguish. If you knew that the next pair of shoes you purchased you would be stuck wearing every day for the next year you’d wring your hands just as much. The internet lifeline needs to move to the watch. There it also won’t be dropped and doesn’t require one of your hands to hold. You are then free to choose the screen size that you need for that days activities, just like you do your shoes.
IPad
The screen is to the iPhone as the keyboard is to the MacBook Pro. Why permanently attach a keyboard when I either don’t want one at the time or have different keyboard requirements? Some days I want a numeric keypad and some days I don’t. The iPad’s rate of growth has slowed but it will steadily continue to grow. Eventually the iPad will dwarf the MacBook Pro since most consumers find both the tablet form factor and iOS more comfortable.
Mac Pro
Not everyone is going to want to go all iPad. Apple needs to keep a heavy duty work machine that is the true “Pro” tool. Unconstrained from needing to run on battery power and portability this machine will be able to go where no iPad can. It will be the equivalent of a 1000 horsepower monster truck. With the fall of the MacBook Pro there will be a corresponding rise in the importance of the Mac Pro.
You could make a case for reducing this list further to only the Apple Watch and the Mac Pro. I believe that the iPad will take on the majority of the MacBook Pros market but you could take the view that there are really only two value propositions and that screen sizes are secondary.
- Communications - Connecting to the internet
- Work - Crunching data and creating things
In this case, the iPad is simply one of many sizes of screens that the user chooses. However, I think it will be such a large category that it demands calling out. The iPad is the Macintosh that lived in the shadow of the Apple II until the public finally caught on.