Hi Alan|Cvette,
We already have that aboard - the avast webshield is protecting you, and FlashGotters and NoScripters of all lands have been protected against previous, present and future threats from the day FG and NS came around and with Request Policy extensions to top it off, I will browse my Fx or Flock browser with full confidence. And if NS extension would come to Chrome or SRWare’s Iron I would use that browser for the additional built in tab “sandbox” security that now has landed also in Firefox 3.7 Minefield. So there is still hope for you and your dream has already been realized, you just have to install it, and then the people of Shadowserver Foundation are working your dream every day: http://www.shadowserver.org/wiki/
I wish you Merry Christmas and a Happy NewYear,
pol