IMO both consoles and handhelds are here to stay.
Sony fumbled many things with Vita, but there's still a market for a portable Playstation, it just needs support for more AAA western games and to use cheap memory storage.
3DS had a fumbled launch, but it's still sold very well and the New 3DS will breath life into the platform, along with continued game support, Vita can still have that too.
As for home consoles, cloud gaming can't match dedicated hardware, the experience is too unreliable and costs are an issue, because no one is going to be willing to a subscription service every year, nor will software publishers be willing to reduce their profits to support this kind of business model.
PS Now will work because it's a supplementary service, provided the pricing isn't much more than PS+ and it works because it's for games that have already sold through their margins, so publishers just get a bit more revenue from it or a lot depending on the game.
No one will be willing to pay hundreds to thousands of pounds per year for something that will be less reliable than their home console, that they don't own.
We're back at Xbox One, 24 hour check-ins being forced on people.
When games like No Man's Sky can generate an entire galaxy's worth of experiences for gamers the cloud is a useless prospect for a games platform.
9th gen home console tech will make AI, physics and all of that a vastly superior environment compared to this generation, just like the 8th gen is to the 7th and the 7th was to the 6th, so on and so forth.
Latency will be even more noticeable because processing technology on a die is getting even closer together and huge amounts of memory will be stacked on a processor, local bandwidths are going to get ridiculously quick over the next few years.
