Chris,
The E5s is not a new model coming out. It is a regular E5 which has been stretched to become a lightweight 600 size bird. Simply a longer tail boom, 600 size blades (606 Rail Blades in the video) and generally run as a 12s setup.
That is just one of the many great features of the E5. You have the ability to stretch it to a 600 class should you choose.
Cheers,
Mark