Today, Apple released all of the minor updates that it's been testing since early February, including iOS 13.4, iPadOS 13.4, macOS 10.15.4, watchOS 6.2, and tvOS 13.4. This was actually announced last week alongside the announcement of new iPad Pro tablets.
That's because the newer iPad Pros, including the 2018 model, have a new keyboard accessory that has a trackpad, and a key feature of iPadOS 13.4 will be trackpad support. Another feature is folder sharing in iCloud Drive, something that will also arrive in iOS 13.4. You'll also find better options for editing and viewing permissions.
In watchOS 6.2, you'll find that ECG is now available in Chile, New Zealand, and Turkey. This update also enables in-app purchases on Apple Watch apps.
These are, of course, minor updates, so you're not going to find any major game-changing features. Those kinds of features will instead be reserved for the major updates that we'll see this fall. We should learn more about iOS 14, macOS 10.16, watchOS 7, and tvOS 14 at WWDC in June, and you should be able to test out the betas immediately after. This is, of course, assuming that things are still on track, with the COVID-19 coronavirus delaying things.