One of the cooler toys that came with Windows Vista/Windows 7 was the app preview from the task bar.
Mouse over an open program like windows explorer and a preview of the app appears in thumbnail form. This feature is especially handy with apps like Internet Explorer, which can have many tabs open simultaneously. A preview window opens for each tab in IE.
By default, Firefox does not enable this feature; it only displays one thumbnail with the current page running. Frustrated by this limitation, I stopped using tabs so each page would open in a separate window. Each window appeared as a separate thumbnail, but losing the tabs within Firefox felt a little too... last decade. Fortunately a quick google search pulled up the solution.
Firefox can enable the windows aero thumbnails for each tab through a configuration option. In the address bar, type about:config.
In the filter, type browser.taskbar.
Double-click on the browser.taskbar.previews.enable line (bold above) to toggle the value to true.
I had to restart Firfox to get the change to work, but now it shows thumbnails for all open tabs just like IE.