Drupal 8 won't kill your kittens - Lee Rowland
There have been a lot of discussions around changes in the Drupal core team and that many old names are leaving for a variety of reasons, however there have been many new people coming on board and any community should be able to move on from it's originators. I'm currently going through the same process myself right now with Green Renters and it can be a difficult but worthwhile process. This was a  great oversight of what is new in D8, watch presentation
Remember Lee's final words… "We will accept any help"
See the presentation here

Twig: Drupal theming in the future - Gordon Heydon
Twig is to be the third Drupal theming engine and it's largely taken from Symfony alongside a few other components. It strips a lot of extraneous php code from templates. Have a read about Twig generally here and Drupal's Twig implementation here.

A subtext of all of this is about making Drupal less specialised and specific, is this needed? Does it take away the uniqueness, will it help bring more into the mainstream? That all remains to be seen…