What have you done to windows 8 ?
He switched to Aero Lite theme in Windows 8. This theme is ugly, because it makes the scroll bars look ugly, the close/minimize/maximize buttons look ugly, and everything else look ugly. The ribbon itself is ugly. The Aero lite is for the server version of Windows. It can also be synced to RTM if you have been using Aero lite in the RP version. The method he showed is way to complicated than the simple steps you can follow to get back this ugly looking Aero lite theme. Bing it (or google it) to see how to enable Aero Lite in Windows 8 RTM.
But seriously, there is no reason you should be using this ugly theme. You are giving up good UI controls in return for an opaque taskbar. Switch to the RTM theme and see how beautiful it looks compared to this server theme.
Also, the taskbar is transparent for eye candy. It follows the digitally authencticaty by being flat and "modern looking". It's not glass, but, rather, it is trying to show the wallpaper while keeping the taskbar vivid. Window boarders work better without transparancy because transparency with overlapping windows look ugly. And the transparency on task bar was intentional according to the MSDN blog.