I saw Sega go, commodore go, Amstrad, Atari, NEC and so on and so on. Sony, MS and Nintendo are then not permanent in the slightest, Sony and Microsoft indeed being upstarts after a fashion and Nintendo would have been were I older still. All have had serious blows to their bottom line and financial health over these last years, and while they may have the funds to cruise for some time to come I imagine their investors would shred them before that happened.
As far as consoles go some have wondered if changes are afoot -- locked down consoles a la what Nintendo brought to the world (compared to all the other non Sega Japanese and European stuff) are something of an anomaly or artificial construct. It made some sense in the arcade era and there were ways to do styles of computing with specialist hardware for it (scrolling games for one), today it is all much of a muchness. While it is always going to be nice to have more performance to give to overhead there could be a little plateau before we get some really really easy programming languages made.
Inventing the console as a concept today seems much like all those android tablets that have the android store absent and something else there instead -- technically possible but you will be questioned on why you would. Even more odd is Sony and MS seem content to do basically identical devices but keep them separate, though I will have to figure out what numbers they get from their cuts, release fees and online services before I go in too hard for that. Back when there might also have been a measure of creative control blocked but today you will be hard pressed there.
Nintendo have not really done anything interesting in hardware in many years at this point, and I will include controllers in that, and often have their poorer hardware hamstring them. Worse still is their hardware is seldom a great way to experience gaming as a whole these days -- I don't like exclusives as a concept but looking at Sony's and MS' PS360 and beyond offerings I could live without it and still experience what gaming has to offer, not so on Nintendo's hardware. To that end I would like to see them go pure software dev. After playing the switch at the press event I said not the path for Nintendo to go to the land of milk and honey, I stand by that remark. Once the infatuation wears off... we all enjoy winding fanboys up.
Sony. If their executives take too long to die or step down, their TV division underperforms a few more times (entirely possible as it seems nobody really cares about 4K, 120fps, curved TVs, 3d or HDR, and a few other makers made the "mistake" of having their 1080p screens go the distance a la the CRTs of the 80s and onwards) and they have some other of their bases shift underneath them I can see something interesting happening.
MS. As mentioned they are already doing some kind of exit after a fashion. With that said they have a serious gaming pedigree and will likely be a serious element of the games world for some time to come.
Going a bit more off topic. People seem to mention console makers as being something special, similar to how semiconductor companies do or do not build their own chips. To me that seems odd in a way. My such a list of gaming industry heads would have to include EA and Ubisoft, and maybe a few others too (Konami and Capcom might once have featured but they lessened themselves over the last decade or so to the point where I am not sure they need to be). A good start for such a list is probably anybody with a stage show/hour long show in E3 or their own conference of note. Some game dev running up to me and breathlessly saying they are releasing on Sony or MS seems much them saying we are putting out a blu ray (or DVD 15 years ago) and as much reason to be excited as such a thing, that is however without the perks of the DVD model. In a world where Disney can buy Fox I am hoping something silly like Sony and MS partner up to generate a console standard comes to pass, even better if it might offer some competition to android (something my lack of mentioning thus far will probably be an apparently massive oversight in 10 years*).
*before someone says "android will never", consider that such a sentence once ended "be the primary way many people access the internet". Consider also all that it can emulate. Someone, or enough someones, will stop milking kiddies for their quarters like grandpappy used to do in the arcades before too long.
To add on to the first paragraph I have seen the quasi breakup of IBM, AOL are nowhere near what they once were, nobody is quite sure what is happening to Dell, Microsoft themselves have taken an odd path (though one many can understand).
