Well, I didn't get it quite like you, Kangal.

He never said that desktops transformed into laptops, those into smaller form factors, and so on.

On the contrary, he says these devices are complementary, and I agree.

I have a powerful desktop, with two large monitors. I use desktop applications, IDEs. I would never give up my desktop machine for a smarphone, however smart it is - there's just not enough screen real estate, etc. to use those desktop apps. Even if I could, it would be inconvenient to say the least.
With a smartphone I want do quick stuff on the go, but not serious work, and for that I need apps that are optimized to small screens and touch input.
All these devices are not replacing each other, but complementing. That's why Google refers to tablets as "the third screen", desktop/laptop and smartphone being the first two.