Apple may be close to releasing the first update to Watch OS, along with an SDK for the Apple TV.
Watch OS, the operating system for the Apple Watch launched back in April as version 1.0. It was roughly analogous to iOS 8.2 on the iPhone. iOS 8.3 has since shipped for the iPhone, iOS 8.4 is in beta, and iOS 9 will likely be previewed at WWDC 2015 on June 8. Apple has also promised an update to WatchKit, the Apple Watch developer framework, to allow for full-on native apps.
How all of that maps to a potential Watch OS 1.1 or Watch OS 2.0 releases is uncertain, but Mark Gurman has reported the following on 9to5Mac:
Besides working on allowing developers to build native, full-speed apps for the Apple Watch, Apple is working on allowing third-party watch face "Complications," according to our source. Complications are the small widgets indicating activity levels, battery life, alarm clocks, upcoming calendar events, and the current temperature on many of Apple's included Apple Watch clock faces. Our source says that Apple is currently testing a new version of Watch OS that notably includes a set of Twitter Complications. For example, a small Complication could display a count of unread Twitter mentions, while a larger view could show the text of a recent Twitter mention.
In addition, Gurman reports that Apple may release the long-rumored "TVKit", its development SDK for the Apple TV, allowing developers to make television apps as well.
Apple is also working on OS X 10.11 and more, which could make for a very busy second week of June, assuming it all hits at the same time.