I sat through his talk and I definitely recommend taking a look at the slides. The new language features are exciting (like argument unpacking in function signatures [1] and constant scalar expressions [2]). What was really useful was learning how to deploy atomically without killing existing requests[3].

[1] - http://talks.php.net/wepay14#/php56unpack [2] - http://talks.php.net/wepay14#/php56constscalar [3] - http://talks.php.net/wepay14#/7