My first impression is, we already have this game on our shelves
Same here, but I think we just heard news about the very basic version of 5E.
I would have much rather seen them go forward, rather than this whole zen approach of starting from basic D&D, and building up again, to rediscover the game of Dungeons and Dragons.
They don't want to keep moving from 4E, no judging if it's good or bad here, but 4E split even more D&D and they feel the urge to try to reunite. It's a valid starting point, being a success and a failure.
In 4th edition I feel great freedom in the DM chair to create adventures, to create a campaign, exactly the way it is in my vision.
That's where experience varies. I found DMing 4E easy and relaxing. Monster Builder is what every DM dreamt about. No need to deal with unbalance was my greatest relief.
On the other hand, I didn't find this freeedom you talk about, on the opposite, I was always constrained by rules that never made sense to my players and the lackluster rules for out of combat experience.
The laziest part of 4E is what some people think it's genial, page 42... but it just me and I'm not owner of the truth here.
And we have to consider people's opinions. You think it's one step forward, I think it's one step in a 45 degrees angle (good, but in other direction that doesn't feel like what I think is D&D) and some people think is a step back.
but 4e challenged some of the prevalent D&D assumptions at the time and indeed made the game modern in rules (without impacting whatsoever anyone's ability to RP to their desires)
That's not entirely true in my opinion. 4E went on a modern direction, yes. 4E is a damn fun game, sure. But a lot of rules killed disbelief suspension for a lot of people around, so I don't think it's true to every people around that 4E didn't impact on RP.
4E is very good at combat, but lacks in out of combat games... not to mention that some less realistic rules killed immersion in my group's experience... that don't killed our fun, tho, we use 4E when we feel like having a heavy focused combat game.
TLDR, 4E impacted on RP abilities for many people.
I think it's definitely too early to dismiss the new edition as unsuitable for 4e fans, and my advice to 4e fans (of which I'm one, although I also like the older editions so I like what I've heard so far) is to withhold judgement until you've seen the modular stuff that's designed to appeal to you.
I got this impression DDN is Essentials in reverse. First you got essentials, then 4E.
Just hope that some of 4E innovations are available as options right at the start.
But why would a 4e player want to do that, if s/he can get the desired game right out of the 4e can?
It's another game.
It's not 4E. If you want a 4E, stick to it. As people who want PF or 3.5.
It's another edition which aims to cater 1 to 4 playstyles... but it's a new game.