In Safari 4, zooming would make everything bigger and your screen would appear to have jumped to some other point on a webpage as the text/pictures/video that were above pushed what you were looking at off screen. Now, zooming keeps what you were focussed on dead center while making everything bigger (or at least does a better job of it). It's a very minor change but it's greatly appreciated :) No more having to zoom and then re-scroll to where you were on a page.
[crarko adds: I tested this, and it works as described. Safari 4 did have its fair share of wonky behaviors.]

