The iPad Pro's screen will have a resolution of 2560 x 1920 pixels, Alexander predicts, giving it a sharpness of 248 pixels per inch. That's not quite as sharp was the 264 ppi screen of the iPad Air, nor even the 326 ppi screen of the iPad mini, but given you'll be holding the Pro farther away, it should do just fine.

Other rumours have it that the Pro will include Force Touch, the amazing fake-clicking technology that Apple has already added to its Watch and to the new MacBook, and also the USB-C port that has already appeared on that MacBook. Wouldn't it be fun if iPads used the exact same cables as all your other devices? That's what USB-C promises.

Yet more rumours have it that the iPad Pro will also have a pressure sensitive Bluetooth stylus, just like Microsoft's Surface line of tablets, which like the putative iPad Pro are designed to double as notebook PCs with the addition of a keyboard.

But unlike the Surface, the iPad Pro will also certainly be running a mobile-phone-class operating system, iOS, on top of a mobile-phone-class processor, meaning that you might have a screen the size of a regular notebook, but you won't have the full functionality of a regular notebook.

(The Surface Pro 3 runs Windows 8.1 - soon to be Windows 10 - atop a full-blown Intel Core processor, while the Surface 3 runs Windows atop an Intel Atom processor, more akin to the ARM processor that doubtless will be in the iPad Pro, if and when it eventuates.)

If Apple actually is looking to replace the MacBook Air with an iPad Pro, now is a better time to do it than last year would have been, when the iPad Pro was originally expected. That new MacBook mentioned above already supplants the MacBook Air in very many respects, so MacBook Air owners who don't want to switch to an iPad Pro for their productivity needs would still be able to stay in the Apple family.