Consistent design and syncing across devices on all platforms
It has been 15 years since Google first appeared as a search engine, and on its anniversary Google is rolling out new search features to mobile devices. First up is a new and improved mobile web search experience across all devices, which puts it more in line with the "card" view of Google Now. Search results are now cleaner and more touch-friendly, focusing more on clusters of information in individual cards to help you get what you need.
On the back end, Google is laying out new improvements in its search algorithms and new keywords in the Knowledge Graph. For instance you can now ask for a comparison such as "compare butter with olive oil" to receive a nutritional breakdown of each, or filter down results with a broad query like " tell me about impressionist artists" to get information about who those artists are and view other artistic genres.
Google is also improving cross-platform syncing of Google Now actions with all of your devices. With updated versions of the Google Search app on Android and iOS, you can now set reminders or calendar events with Google Now on one device and receive the notifications (even location-based ones) on the others. It's all about making Google's services ubiquitous across platforms, and as always they indicate they're just getting started.
Source: Google Search Blog