On one hand, I'm pretty inclined to agree. It would be too risky for anybody else to enter it. The whole random consoles being made by everybody thing is most likely dead forever. But then again...
This is also true, nobody could have foreseen that Sony would bust in and own business. They really were not associated with games at all before, and now Sony and games go hand in hand. It's tricky to predict sometimes... But they were already an electronics company, and still are, and a huge company before they entered the race, so... Who knows anymore.
This is how I feel about handhelds as well, but I still think it's a possibility. Especially with wireless capabilities growing and growing. I could easily see a handheld that can be programmed to appear on certain televisions when it is close enough, making it both your portable device and console at home.As for whether or not consoles will be replaced by something like handhelds; I doubt it. I personally don't like playing handhelds. I don't travel enough for it to be worth having for long trips, and when I do travel, I'm usually doing the driving so they're useless to me, and if I'm at home, I'd rather play on my 27" TV with surround sound. Handhelds are huge business, but a replacement for consoles they are not.
They were already talking about making the next-gen systems entirely wireless, it just didn't happen. It will with the next probably, and then a smaller gaming device like the DS that appears on your television would be the next logical step to me. Nintendo has kind of proven that it's not really about graphical power anymore, as long as it's kinda pretty that seems to be good enough for most, so making these huge consoles like they are now is becoming unnecessary for profit.