I just gave a short presentation on JUnit 5 at my company, Fortitude Technologies. JUnit 5 adds a bunch of useful features for developer testing such as parameterized tests, a more flexible extension model, and a lot more. Plus, it aims to provide a more clean separation between the testing platform that IDEs and build tools like Maven and Gradle use, versus the developer testing APIs. It also provides an easy migration path from JUnit 4 (or earlier) by letting you run JUnit 3, 4, and 5 tests in the same propject. Here are the slides:
JUnit 5 from Scott Leberknight