I think you are establishing a false dichotomy between DMing styles here.
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When you are practicing scene framing, you handwave the "boring" parts and jump to the conflict, so I don't think having a Thief Acrobat walking a tightrope (without external pressure) would be more than colour in your game. For more than 20 years now, RPG have had guidelines about when to roll or not to roll. In 3.x, it's even called "Taking 10"
I don't agree that the contrast in styles is a false one, although I'm happy to agree that presenting it as a dichtomoy is abstracting the tremendous variety of actual approaches into a couple of stereotypes.
The very fact that, in the D&Dnext materials, the rules about when checks are appropriate are presented in the DM Guidlines and not the How to Play document, speaks to me of the contrast that I pointed to. And I've also experienced it, particularly in playing 2nd ed AD&D. And I see evidence of it in RPG discussions all the time.
I also think WotC did a decent job with their exploration and social interaction frameworks, so I am quite optimistic concerning the downtime implementation.
I don't have a strong view on the exploration system. I started a thread on the interaction system, where I set out what I do like and what I would like to see changed a bit (mostly, multiple rolls to allow dynamic but non-fiated evolution of the situation during resolution). The downtime system I will wait and see on - I've said what I would like upthread, but I'm not confident that WotC will necessarily go that way, rather than in a more AD&D-ish direction.
In its essence, 4e combat is closer to a game of Magic than a wargame using minis
I've played a bit of Magic, and quite a bit of 4e, and I don't really find this to be the case at all. Even the role of standardised templates for "moves" is very different, because in Magic keywords are purely for establishing interlocking mechanical effects, whereas in 4e they also establish fictional positioning. But the essence of 4e combat, for me, is that it has mechanics that permit expression, in the fiction, of the protagonistic desires of the players (action points, powers of various depths at various recharge rates, a sophisticated action economy) - this is something that D&D spellcasters have always enjoyed to some degree (do I use Magic Missile or Lightning Bolt?) but stepped up even for them, I think, and certainly stepped up for other PC types.
This contrasts with AD&D where the player of a fighter has no way of mechanically expressing his/her desire to have a greater or lesser impact on the situation in any given turn, and even the player of an MU can only express this by choosing a higher- or lower-level spell.
In Next, I can see this sort of mechanical feature in the fighter's Action Surge and Weaponmaster manoeuvres, the warpriest's extra attack ability, and the rogue's Ace in the Hole (though that doesn't kick in until 20th level). I think they will need more of this sort of stuff, spread over more classes, to emulate 4e.