Most exciting for me is really that this opens up the web for true cross-platform development. The same code runs natively on iOS, Android, Raspi, Linux, Windows, Mac etc with the smallest possible footprint and highest performance, and at the same time I can take the exactly same code (minus a few hundred lines platform-specific stuff) and have it run in the browser at near-native speed, without installation, code-signing, walled-garden app stores, 'smart-screen' scare dialogs, etc...

You just compile, upload and share the URL. Like in the old days ;)