[randall]

Is there anything preventing you from using non-native elements right now? I mean the <html:html> weirdness aside... can't modern browsers just recognize current <weird><tags> and process them as such? Why not just have HTML keywords be hands off for your app and then do your own thing with the element syntax? That's what Angularians are doing.

[adwf]

Some of them already do. I use <p10> as a style tag on some websites and firefox/chrome deal with it fine. The advantage is that old versions of IE don't, so it's a simple browser detection for the user support team. ie. "Is the text in the top-right black or bright green?" "Ok, you need to update your browser..."