It’s certainly a novel direction to take the MacBook line, adding dynamism to a keyboard layout that has remained the same for many years. A lot of Windows laptops includes a row of illuminated capacitive buttons but Apple is going further. It’s essentially replacing the function keys with a (really skinny) OLED touchscreen that can display any arbitrary UI. I think Apple chose OLED for the contrast levels, I can envision how the deep blacks of the screen look great alongside the piano black keyboard keys.
It’s not obvious to me how Apple is going to use this secondary display. Because it isn’t the primary display and because it can’t be a mandatory requirement to use OS X, as Apple will still be selling millions of Macs without a OLED accessory bar, I fear it might be an underused gimmick.
As Nintendo fans will know with the Wii U, making interfaces that interact between multiple screens is tough. What happens is that both displays battle for the user’s attention simultaneously but it turns out that ultimately one screen naturally monopolises the focus. In the case of MacBook, the primary canvas is the 15 inch Retina display. Demanding the laptop user to look down constantly is laborious and annoying. The natural laziness of people means most do not want to be nodding dogs; there’s a reason why touch-typing is so popular. Aside from physical strain, juggling multiple displays is simply a lot of information to take in. Creating UI conventions to signal when users need to check their dashboard display is incredibly hard. Putting critical information on the secondary display is a risk if the user simply forgets to check it.
The other end of the spectrum, then, is to keep the OLED screen content pretty much static. Limiting dynamism simplifies the mental load and enforces clear patterns of expectation about when the user is supposed to interact with the accessory display. Perhaps preferences allow for some customisation of what can appear there — the crucial point is that the buttons wouldn’t change passively whilst using OS X.
Although that would remove the problems I enumerated, it is a functionality tradeoff. What I’m describing in the second case is not that far removed from what exists already, i.e. a fixed set of function keys. In fact, it would be a regression in this case: the tactility of actual physical buttons would have been sacrificed. This is why I’m in a quandary. I would be concerned if Apple incorporated a significant new hardware change without a compelling use case to justify its existence.
A lot of people could argue that Force Touch was exactly that, a Mac hardware feature that was/is a dud. The impact with this rumour has more potential to be destructive. Force Touch on OS X can simply be ignored with no downside. An OLED button bar that replaces function keys cannot be ignored, it will have to be used by every new MacBook Pro owner. If its bad or mediocre, every customer will be impacted.