There seems to be the thought that it could be possible, in the near future, to search without a phrase or term. But what are you searching for without a topic? Google has long been in the business of not only helping you search, but knowing “you”. It’s in their best interest to know you as well as they can, so they can serve your needs and desires.
With Google Now, search became a nearly miraculous method of providing you the latest information about what you want to your phone. So for example, you search for the local hardware store from your desk and before you’ve even left for it, Google Now has provided the directions, travel time, and current weather. Google knows you, likely better than your friends.
So to search for “nothing” would actually be a search for what you may need in the moment. Say, for example, you’re stuck in traffic on the freeway, most likely you would want to know where the holdup is, or where you might travel to avoid the rest of the traffic. Google Now would be aware of your current situation because of your recent travel speeds and would serve you transit info and possibly traffic reports, before you search for “traffic reports”.
With time and usage, Google Now can already give both ETAs in advance of future travel, based on where and when you travel. But with Searching for nothing, it may be possible to nearly predict the future on-demand for a limited scope of personal possibilities.