Both improvements bring more visibility to kinds of data that would otherwise require clicking through to the source site. Google now does much of that work for users by bringing relevant, formatted data directly to its search results pages.
Between the two improvements, the highlighting one is the most interesting. It now highlights what Google calls "answers" within page summaries. These are matches to a user's query, so if a user looks up something like a math problem, or a semantic question such as, "what is the capital of Haiti?" the answer would be made bold right on the page.
Google's example for a before-and-after goes like this (before is on the top):
The tech that powers this comes from Google Squared, which can take data from search results, find matching sets, and chart it out automatically.
While, Google says the technology works well for this application, when users are looking for a single piece of data, as opposed to a broader query better served by something like a subsection of a Wikipedia entry.
The other new feature introduced alongside the answer highlighting is an additional rich-snippets format for events. This will take properly formatted event information from pages that contain events listings and put them within Google's search results. This lets users eyeball things like upcoming tour dates before ever venturing onto the site that lists more detail about those events.
It looks like this (highlighting mine, not Google's):
In order to get the new rich-snippet style to work, site owners need to add a small bit of formatting to their content that will make it easier for Google's search spiders to take that data. It's a similar type of effort that was required to be included in the company's other rich-snippet styles for review ratings, videos, and people.
The events rich-snippets feature has been pushed live. Google says answer highlighting will be introduced to users over the next few days.