I am able to replicate this in fullscreen and maximized mode. Windowed mode doesn't seem to have this issue for me. When zooming in or out, the focal point of the zoom is dependent on which edge the cursor is hovering above. For example, the right edge will zoom focus further to the right side of the world coordinates. Also, if I alternate between zooming in and outward in succession, the view essentially pans towards which ever direction of the edge the cursor is hovering.

True, we'll make it so scrolling at the very edge of the window doesn't scroll the viewport.

@SilverStraw, I'm not sure if you consider the behavior undesirable or if you're only stating facts. It's working as designed, allowing you to effectively pan by zooming in/out. Removing the need to pan soon becomes second nature and is much quicker than the more simplistic zoom-to-mouse that most apps use.
User interface - Spine User Guide: Zooming

Just stating facts.

That's cool! 8)