Simply open System Preferences, go to Trackpad, and uncheck the box at the top saying 'When using gestures to scroll or navigate, move content in the direction of finger movement.'
[crarko adds: This was the very first thing I did after the scrolling in Safari started driving me nuts. I also found it absolutely essential to check 'Ignore accidental trackpad input,' as the sensitivity of the Trackpad on the MacBook had been greatly increased.]

