That is not viable though Adam as web apps is only the top end plan and its a costly part of the system for BC. I do not believe that is the right approach and web apps are awesome but not the solution to all problems.
So I do not see that happening at all, and I would say that is a bad idea. Going through the elements and just tweaking them into the new rendering engine with the JSON output for them and just working on the core aspects of them with liquid output means that they wont have to focus massively on the front end rendering, but with the data accessible and the fixes, tweaks and features in them means a lot more.
You already have MASSIVE flexibility and control and ability with custom CRM fields and how you link them not to just a CRM person for example, but there isn't the front end rendering to do as much as you want with it. This is one of the core goals of BC.Next to have the engine in place to make all this possible.
Anyone trying to do apps that involve content, such as events and the WYSIWYG aspect, browsing for files etc, will all (And I know many have) run into the core problems with those at the moment.
The file manager I have built for some of our apps has taken a lot of time alone, and lacks some features you just can not do without the API for them yet, and any editor will lack things like the custom class dropdown, custom internal links, those BC Models etc. So in terms of those aspects, actually content formation by the client will be less, then with the core.
Not saying not go for it, just stating why there are some apps we are avoiding for good reason