Zeev Suraski spoke about PHP 7.0, which is currently due for release around mid-November 2015. As we often are for WordPress before a new release, they're looking for testers! He highlighted that performance, particularly comparing with HHVM, will be one of the big improvements to look forward to.
If you're after more detail on the release timeline for PHP 7.0, there's a PHP Wiki article for you to check out.
While it's going to be some time before you can realistically write WordPress plugins that take full advantage of the new features coming in PHP 7.0, there is hope: a throw-away line from Matt Mullenweg's Q & A was “I think that maybe this might be the year PHP 5.2 goes away.”