If you want to find nearby events online, you often have to go directly to dedicated services like Bandsintown or Eventbrite... or worse, flip through the calendar on your favorite nightclub's web page. Why can't you just search the web and get some timetables? Google is enabling just that. It's adding an event search feature that lets you sift through happenings based on where and when they take place. If you're hunting for upcoming jazz concerts or just want to know what's going on this weekend, you don't have to visit specific sites.
In case you're wondering: no, Google isn't trying to replace dedicated event services. More often than not, it's just pulling information from those pages to put them in one place. The difference is that you don't have to go to each of those sites to make sure you aren't missing an important gig -- you should get a more comprehensive view of goings-on without much effort. If you end up catching a show that you know you'd otherwise have missed, you'll know who to thank.