How do I view the content of the Clipboard in Windows 8?

True. There is no Clipboard viewer application included in Windows 8. Try a free application like Free Clipboard Viewer.

I have just learned from Wikipedia that it is possible to copy the executable from Windows XP and use it in Windows Vista, 7 and 8. See here for details.

Save.me

A Clipboard Manager For Windows XP, Windows Vista, Windows 7 and Windows 8. It automatically saves everything you are working on, including text, images, URLs, files, and folders. It lets you manage the clipboard entries, letting you add new items, edit them, save them in files and delete the unneeded ones. You can even preview any saved clipboard item from right within the app. Save.me is a portable application and can be launched directly from your computer or even a USB flash drive. Once started, it runs in the system tray and saves everything you copy to the clipboard.

Example Screenshot:

Edit

Alternatively you may be in interested in an Application called:

Keeeb

Dubbed "The Next Generation Content Curation" - Offers A Softboard For Bookmarking & Organizing Web Clippings and boasts a special import function that allows users a smooth transition from Clipboard by migrating their existing clips.

A review of it was carried out recently here.