We don’t have plans for an iPad pro version at the moment. Yes, it has a beautiful screen, but there’s more to consider, such as how to adapt the UI for touch without compromising the experience.
But the biggest problem is the platform. Apps on iOS sell for unsustainably low prices due to the lack of trials. We cannot port Sketch to the iPad if we have no reasonable expectation of earning back on our investment. Maintaining an application on two different platforms and provide one of them for a 10th of it’s value won’t work, and iPad volumes are low enough to disqualify the “make it up in volume” argument.
The paradox of information goods, which is that you only know wether it was worth the price after you have bought and consumed the good, still applies to software.
Being unable to provide trials to minimize that problem leads directly to prices that are unsustainable for applications that might otherwise be profitable. (The other route are in-app purchases.)
It is rather fascinating that Apple has still not addressed the problem that is a lack of trials. It might be indeed that Apple still does not see itself as a platform company. (For more read Ben Thompson on the state of the iOS platform and what Apple should do, but probably won’t.)