anti virus only protects from known threats
Bollocks, many major antivirus programs now have behavioural threat detection which looks for suspicious program behaviour, not simply signature. Signature-based scanning has been of dubious effectiveness for years, and while it's still a good way to efficiently block known threats, behavioural scanning is what protects you against new ones.
I agree with hotwire_downunder that this research is very sensationalist, though it does have some useful findings; most important is the continuing reliance by anti-virus software on administrator level privileges. We need better operating system support for anti-virus, and by extension anti-virus programs that don't need lofty privileges in order to function; all they really need is the ability to signal to the OS that a program or file may be infected so that it can restrict it, at which point a user can provide administrator support to fix/remove it, the program shouldn't need that kind of access all the time.