This behavior can be startling if you're expecting the old behavior. The key is to understand how the new behavior works.
Start the zoom by clicking on the area you want to zoom into and keep the mouse button down. As you drag right, you zoom into the point where you initially clicked. As you drag left, you zoom out from the point where you initially clicked.
If you decide that you still prefer the old behavior, you can disable the new behavior by selecting the Zoom Tool and unchecking "Scrubby Zoom" on the tool options bar: