I think there's always going to be a demand for games running on local hardware, in the same way there's always demand for high end GPUs/monitors/etc even if it's only a small proportion of gamers who are actually willing to fork out for it. So I don't think PC or consoles are going anywhere.

I do think it's inevitable that Cloud gaming will get bigger and bigger though. In fact I'm sure that over the next decade or so it'll probably overtake the existing medium in terms of market share. The convenience and low cost of it will be enough to offset the drawbacks for a huge number of users.