Agreed on the workflow problem. The pain of using a DSLR has less to do with the form factor (size and weight) and more to do with the fact that the post-shot work is stuck a decade in the past.
And I think that's true even if you're a professional - as a professional, your shots should use your phone's cellular connection to upload the shots to Adobe Creative Cloud (or competing cloud) as you take them, so that when you open your machine to do post-processing work, your shots are all already there. Why should anybody be bothering with CF or SD cards anymore? Just store everything on your smartphone (did you hear the iPhone 7 will now have a 256 GB option?), which in and of itself is a buffer for your work before it gets transferred to the cloud.
Modular backs a la Moto Z are interesting because there's a lot of potential now for making "big glass" relevant again for prosumers. Make a modular back with a large sensor and a Micro Four-Thirds or F mount. The only real problem is getting OEMs to agree on a common standard that they would stick to for years, because nobody wants to spend hundreds or even thousands of dollars on a camera back they won't be able to use next year when they upgrade their phone, and yes that's actually a really big problem, but leadership from Google (in the Nexus/Pixel lines) can really help here.