Since updating to Unity 3, there's been an issue with the view camera where instead of dollying (moving towards the target) when scrolling with the mouse, the camera remains stationary and appears to zoom instead.
This makes any terrain or objects on the edges of the map get in the way of the camera, and is making editing difficult.
Is this a new camera setting for Unity 3 or a bug? Please let me know if there's a way of restoring the camera settings to dolly instead.
Hm, I tried 3.0.0b6 and 3.0.0f1, and cannot reproduce this. The editor's Scene view camera should only "zoom" when in orthographic mode (indicated by "Iso" in the upper right corner, below the coordiante axis representation), otherwise it should dolly (indicated by "Persp"). You can Shift-Click the cube icon at the center of that coordinate axis symbol, to toggle between orthographic and perspective view.