There doesn't appear to be, at this stage anyway, a single magic bullet, and I doubt that one is on the way.
You've heard all the suggestions, such as tax changes in charitable status for foundations. In the United States, there is quite a bit of experimentation going on with foundation funding, trying to figure out how to create more sustainable local news ecosystems in different communities. However, the approach they're taking is not to subsidize the production of news, but to subsidize experiments in creating more sustainable business models.
You can subsidize the news, and then when you stop subsidizing the production of news, the whole thing falls apart. The idea and the approach they're taking is to subsidize experiments in, for instance, something as simple as creating a document and a website on basic media law that local start-ups for online organizations can go to.
Those are sort of microscopic interventions, but that's the level of experimentation that's happening out there and the thinking about how to approach this problem while the whole business model issue is still being worked out.