You won't get to shop watch faces, alas, but there won't be a shortage of Apple-provided watch faces. There's a more traditional "California" dial, a gradient face, an analog LCD face and an updated compact Modular face that includes an analog clock. Also, you won't always have to stare at your watch to know the time. Taptic Chimes will tap or make noises on the hour, so you'll know if you're running late.
Some improvements are under the hood. In addition to independent apps, there's an audio streaming API that lets third-party media apps stream through the Apple Watch. You might not feel quite so much pressure to use Apple's official media apps, then. Other additions include web search results and Shazam song IDs in Siri, spoken navigation in Maps and account sign-ins on the watch itself.
WatchOS 6 is expected to arrive in the fall, most likely in September. In the meantime, though, Apple has introduced a slew of new summer-themed Apple Watch bands, including the latest version of its Pride band.