nope - not yet
it currently zooms or scrolls depending on whether you push the mouse button as you roll - unless it's over a fader.
I've requested more than once that the mouse wheel have an option to switch between zoom/scroll (which I like) and more effective fader tweaking (which others seem to want). I don't find the two to mix very well either.
most recently, here
http://www.cockos.com/forum/showthread.php?t=2833