If you're not big on sharing Photo Spheres you still benefit from this move. The tighter integration means that images from other users will pop up more frequently. And, even if an area is already covered by Street View, there's a good chance that the user contributed pics are more recent and of higher quality. That's a boon for you, but it also makes Google's life easier since it can now surface a whole bunch of 360-degree images for places that it hasn't yet invaded with its cameras. Think of it almost like a crowdsourced Street View.