This ComputerWorld article notes that new features will include improved context around queries (suggesting related content) as well as a document and image previewer.
The new Google Enterprise Search is designed to mine data from a host of different sources -- not only on-premise databases and repositories, but also CRM systems, cloud storage, and social media platforms. I can also be accessed via desktop computers, tablets and smart phones.
In recent years, Google has been developing more and more efficient search algorithms, and is conducting research on using natural language in queries. But the barrier to developing a better search engine is often related to mushrooming amount of data that can be hard to put in context.