Hey, I totally agree! That's why I said a new extension (not necessarily a language extension, maybe a file extension that switches to alternate parser like, hmm, ".phpx") and both ways compatible. Including the "new style" would be possible from "classic style" and vice versa.
Disclaimer: Actually a PHP developer. I know for a fact that if your proposal caught on, my managers would not like us to spend time rewriting a million lines of code to what is practically a new language. That doesn't contribute to making money for anyone.