Killer feature the Passport needs to have!
Being such a huge flagship device it would be a shame if we had android apps confined to a zoomed in square like the q10. This can be a huge pain while using apps only designed for a rectangular screen and are not optimised to fit to square displays.
The Passport should have an android compatibility mode that letterboxes the screen vertically or horizontally to allow the entire app to show up on the screen. The phone has enough pixels to letterbox the screen to make a 1080p display. This should be toggle-able on a per app basis to give the best experience whatever app you are using.
I can see why BlackBerry have not currently implemented this on the q10 as the display would be too small to comfortably use but the Passports 4.5" display letterboxes to 1080p would give the equivalent of a 3.98" display (thanks Pythagoras) which is perfectly usable.
I feel like this feature is a necessity for a device like the Passport otherwise a good 30-40% of apps from the amazon marketplace are going to look like junk on its square screen. There are many customization options blackberry could implement with this too such as landscape mode without rotating the display and setting the position of the letterboxes to better facilitate one handed use etc.
Posted from my Z or Q!