The funniest thing is that a lot of the advice that is being given in this thread would have been absolutely crucified during the 4e days. "Fail forward"? DM's deciding outcomes? Ignoring process sim play in favor of more narrative approaches to the game? There are people who are participating in this thread that I KNOW argued against the inclusion of these things in 4e that are now advocating them, completely without irony.
It truly is funny. To me, this has been WotC's greatest success. The fact that they've managed to convince people who absolutely hated these sorts of things when they were included in the game with 4e that they actually like these ideas and that the ideas are completely not from 4e. The change in writing styles is such a huge eye opener.
Tell people that the mechanics should support fail forward because that's more fun and everyone and their mother will come out of the woodwork to tell you that this is not D&D and is a terrible idea. Tell people that DM's should ensure that everyone has fun at the table and leave it up to the DM's to ensure this, and suddenly fail forward is a fantastic idea totally supported by D&D.
The the greatest triumph is that the people who argued against it ten years ago are now the biggest boosters and will STILL insist that they don't like 4e. LOL