Apple just released the first update to the Apple Watch, taking it from version 1.0 to version 1.01. I just installed it by using the Watch app on the iPhone, which downloaded the 51.6Mb file and then installed it to the watch. There were no issues and it took about 25 minutes from start to finish. For some reason the download from Apple took longer than expected, but otherwise it worked very well. 
Apple published some update notes, which include the following improvements:
- Siri
- Measuring stand activity
- Calculating calories for activities like indoor cycling and rowing
- Distance and pace for outdoor walk and run workouts (I noticed this did not work as expected when I took a walk this past weekend, it did not record any activity though I walked about 30 minutes).
- Accessibility
- Third Party Apps – not sure what this is, but some apps are very slow to load (for more on this see this link).
There are also some additional languages now supported.
And while the release notes did not mention it, the calendar app is now bolder and easier to read, and scrolls similar to what you may see when reviewing the day’s schedule in a desktop application. This is more useful on the small screen.