I'm new to all this so I might be missing something. As I understand it is hoped that users will run KDE plasma on most of their hardware i.e. desktop, TV, tablet, phone etc perhaps a number of each. All of this hardware will be interacting/communicating with each other. Would it not add a lot of utility and possibly functionality if there was a server service that could be loaded on to a local server to stitch all these plasma enabled devices together? An example of such a server will be the WEDG: personal cloud server.

I imagine that ownCloud already provides most of what you are wanting: a personal cloud server that your various devices can interact with, sync to, etc. KDE software already works well with ownCloud.

Previous attempts to share widgets have been made using an adhoc, local network approach. This "cloud server" would allow for configurations to be shared between machines I gather?

Exactly