I am not an expert in the area and started reading about messaging just few days ago after porting to the latest release which disabled hangouts. Hence my understanding can be patchy.

From reading about telepathy framework and your proposal, I am wondering whether its better to focus on already developed telepathy and develop around it. From the look of it, you should be able to make new plugins for new network types and make it all accessible through the whole system. As far as I can see, its possible to make modules in python as well via PyGObject, if you wish.

Taking into account closed source components, you would probably need to implement Accounts and Messager. But the whole lot of work on making parts work together, designing API for communication and implementing it, has been done already.

There is a mention of issues regarding telepathy. Which particular issues do you have in mind?

Do I miss something vital here that makes it better approach to start developing a new framework from scratch?