Ok, not ‘gone’. But quickly overtaken in the consumer marketplace at least. And I bet a lot of businesses too. It’ll be faster than 7 replaced vista.
I wouldn't place such a bet. Win7 was a barely visible improvement of Vista, primarily in optimization of background processes that belonged to two nasty services. The GUI of Vista was similar to Win7 (both are Aero,) and the largest difference was in the shape of taskbar icons. Hardly something to complain about.
Win8 and its successors significantly changed the very process of working with a computer. Now you have additional modes (start screen, the side bar, full-screen configuration panels, and mouse gestures.) Modes are expensive because each time you have to switch your way of thinking. The start screen is not popular because it is cluttered with items that the customer does not need. The sidebar is not popular because it requires a gesture to invoke, and because it doesn't work well, and because it has flat buttons that are hard on eyes. Metro configuration panels are an abomination. Mouse gestures are not something that *anyone* wants to do, as they have zero discoverability.
Removal of Aero and forcing the Metro style, with its flat buttons, is also a bad thing. I cannot even comprehend how stupid Microsoft's art designers had to be to even propose such a thing. There is a technical reason, though, for all this flatness: Aero requires a sufficient GPU to render. This is not a problem in a PC, but it is a concern on a mobile device. So Microsoft sacrificed one of most important usability improvements of all times for sake of tablets and phones - who are not selling well anyhow.
Businesses are not in any hurry to embrace Win8+ because Win7 does its job, it works very well, and there is no need to retrain hundreds of millions of workers all over the world. As businesses use licenses that allow them the right of downgrade, they will continue to run Win7 for a long, long time. Perhaps Microsoft will realize by then that they need to hire someone with a clue.