As a longtime developer using Windows, my dream was to move our desktop machines to Linux ad use virtual machines when needed. Since this was my idea, my windows machine of 5 years was wiped and replaced with Ubuntu. About a month later, I haven't had any need to return to Windows. We use Notes as our mail, so I have a Linux client there. Firefox, Open Office, and my IDES also have a Linux version. My machine runs faster, and it is easier to find things! My music plays fine, and my printers and network were found without issue. Ubuntu is not exactly like Windows, but when you learn the Linux way of things, it works out better actually.
With that being said, the laptop and desktop are being replaced with mobile devices. I don't think the form factor has been settled yet, but "smart phone app" metaphor is clearly the popular OS choice. I love the Linux packages, but the "app store" seems to work better for most users. The good news is those run Linux too.