Todd Bishop:

An overhauled version of the Mac OS X Spotlight search will rely on Bing for web searches, the Redmond company confirmed this afternoon, after Apple listed Bing among the service providers powering the feature earlier today.

Apple knows that the general consumer has too big an affinity for Google to change the default search in Safari, but by doing these little changes with Siri and now Spotlight, Apple is really squeezing Google. If Spotlight starts gaining traction, that is. And that's a big if, as it isn't widely used now (from what I see).