The difference is probably that Microsoft's Windows 10 demonstrations show a manually customized system, while my screenshot shows what it looks like by default

The difference is probably that Microsoft's Windows 10 demonstrations show a manually customized system, while my screenshot shows what it looks like by default, on a newly installed system? Other than that, I'm not sure how I could not be running the current Windows 10 preview, because, as far as I know, it's the only build that supports continuum.