I can't wait to run some code on the Watch. So many people already went ahead and released their Watch apps to the App Store and brag about it on the web, and I am jealous and sceptical at the same time. When companies like Tesla (who will have to release an app for Watch no matter what) do it, they don't care much about the result: they just need to demonstrate their presence at this point, and they'll figure something out later if the app sucks. But I am completely stunned by the amount of small companies and individuals who have submitted their apps now, weeks before the first watch is even sold.
In my opinion, an app should solve a problem. Calendar helps you when you suck at remembering birthdays, Messages connect you to your friends, and Music plays music. But how do you even know the problem exists before anyone actually used the device you're writing the problem-solving app for? How do you know that writing notes on your wrist is a good idea? Sure, you can run your code in a simulator, but to me the idea of writing a watch app today is like writing an accelerometer-based iPhone game entirely on a Simulator and release without testing it on an actual device.
On the other hand, Apple did a pretty good job not giving developers and UX designers too much of a choice with WatchKit. My personal favourite is, page-based apps have to specify the number of pages in compile time. May be I am too sceptical and actually the designers don't have a choice of bad UX at this point at all.