It looks like a Start Button, it is in the same place as the Start Button, but it is not the “real” Start Button. So, it seems the latest rumors about the upcoming Windows 8.1 aka Windows Blue is while it going to have a Start Button, this button does not bring up the Start Menu as one would expect it should. Instead it is going to simply be a way to switch between the Modern UI and Desktop modes.
According to reports, the Windows 8 Start button will reside at the bottom-left of the screen just as it has in previous versions. It will even feature the Windows 8 logo as seen on the Charms bar and on Windows 8-based keyboards. The problem is that the function to switch to the Start Screen already exists at the bottom-left corner – why do we need a button that does the same thing? Will this button make it easier to jump back and forth between Start screen and desktop?
This makes no sense as the same function can be performed by pressing the WinKey+D to switch between desktop and modern UI. I suppose Microsoft misunderstood when users complained about a lack of start button. May be users weren’t clear enough that they wanted a Start Menu, not just a Start Button in Windows 8.
via Tom’s Hardware