Sony, Nintendo and Valve complement each other well. PC gaming should gradually become more console-like for those who want it, so that will provide competition.

I don't think we're quite there yet where there are actual games that require that level of compute power (what type of games and if it's economically viable option is, IMO, another topic altogether). I find that streaming is more about alternative way to play the games you own at visual settings you can't achieve at your home, whether it's about not wanting to upgrade your local gaming device, not having a need for powerful local gaming device, or something else.

I think Microsoft will try and fill their own cap so to speak.
If the next move from them is a flop, it might take some time and then they will appear with a rebrand of Microsoft's gaming division, leaving the Xbox name.
That is at least what I think will happen.

Well the new AI boss already said she is commited to keeping the multiplaform form MS has been going on, so I don't see Xbox pushing any real competition in the console space anymore.

Apple, Google, Valve and Amazon are the only other real technology companies that have the resources to pull it off.

Apple and Valve are the most credible players due to the developer ecosystems they have already fostered... But it's valve with potential console selling games like: Half Life, Portal, Left for Dead, Team Fortress, Counter Strike, DOTA and more that would be the true threat.

A banging Half Life 3 would put a Valve console on the map.

Do you think Sony is not pushing any real competition in the console space since they are releasing games on PC as well?

Is this a serious question?

You seemed to think having own hardware released was not enough to be considered competing in the console space and mentioned multi-system releases as the defining factor that makes someone not competing for real.

Doubt it. Everything gravitates towards multiplatforms.

Where does the PC gets into the consoles competition?

Microsoft started porting their main games to Playstation, the Xbox has stopped competing with it, that's a fact not what I seem to think, it lost 6:1 in January, 8:1 in December. There is no real competiton going on anymore.

In regard to Sony games on PC.

Playstation games on PC had zero impact on Playstation console sales, it's tracking the PS4 pretty much exactly, despite being more expensive and not only not getting price cuts, but actually getting price increases.