Did you not read about phones never becoming as powerful as laptops and desktops? Did you not read about the problem you will have with a small screen? Yes, in the future I will be able to plug it into a big screen, but it will still be a slow processor compared to a laptop or desktop. And did you not read about plugging other things into your workstation? You think carrying an extra screen and Bluetooth keyboard somehow makes it as good as a laptop or desktop? Really?
Let me repeat once more: A phone will never be as powerful as a laptop or a desktop, and will never have the same connectability, nor capability of a laptop or desktop. I am sorry, but you might be able to waste your time using a phone to edit your photos, video, and audio (connected to a (1!) external display), but pros usually have deadlines, and we tend to want to do the hard lifting as fast and easy as possible.
Using your phone connected to an (a single) external display to make up for the small screen would mean you would always need to either carry a monitor to plug in somewhere, or would need to go back to base where the external screen is placed. And then use a comparitively slow processer to do some heavy lifting. How would I, for instance, connect a Red Rocket? An ordinary audio card? A mixer? A proper editing keyboard? And even if all those things were in place and worked, you would still have to deal with slower than necessary processing power, AND need to deal with the shortcoming of a small screen while out in the field? Oh, you want the monitor to be battery powered? Yeah, that's a good idea to make up for the greatness that is attempting to use a mobile phone in a professional environment where you have to have raw processing power to compete. You have to remember you are not only up against deadlines, you are up against everyone else who has faster and better hardware, delivering better results faster. How long do you think you can compete in such an environment? ""Dailies" conversion to format of choice" ring a bell?
P.S. Who on earth said you should take a stonking big laptop or desktop with you to your clients, or that the alternative is paper photos? Online mass storage and USB transfer to your tablet/phone/laptop works quite well. Although, I don't think anyone will be impressed with anything being shown to them on a miniscule phone screen. And with pro video, that is completely out of the question. LOL, I'm sorry, but do you think even a still from an DSLR looks so much better than one from your windows phone when shown to a client on that phone? Seriously, you show it to him on something that he can see the details on. As for dailies, I can just imagine you sitting there for days and weeks on end, getting a backlog that grows by the hour, all to be able to show them the dailies in the format of their choice. Yup, you'd be a hit.