Knockout.js in Magento 2
Magento2 php7 development box
We could argue its still early to start using PHP7 for our next generation webshops. But we must assure that what we build today will work tomorrow. In production environments it might still be early to use PHP7 due to the fact some 3rd party extensions are not yet ready for PHP7. But we can develop just fine on a PHP7 box.