"The Windows 8 kernel is not fundamentally changing any of the algorithms" used in Windows 7, he said. "It's more of a hardened version of Windows 7 … [in that] you don't have any significant structur[al] changes, but you have a lot more checks." http://redmondmag.com
Considering I have had less than one damaging infection per decade in my over 40 years of programming/using computers, I want to have a more valuable reason than "a lot more checks" to switch to Windows 8. Vista had a lot more checks than Windows XP. A lot of good that did. They were so annoying that most people turned them off. Nagging simply does not work!
The major vulnerability to hacking your system is the human that is between the monitor and the keyboard/mouse/touch screen. No amount of increased checking will fix that one. Follow the long published simple rules of safe computing and your troubles will be few and far between. Keep a current backup and you will be able to recover from the few that do happen.
The bottom line is there is no lasting protection from sloth, ignorance, and stupidity.