Those are explicitly abstract. They give only final numbers; they don't describe actions. An "attack" in most versions of D&D is not explicitly described; it's a mix of feints, parries, twists, and so on. You roll the dice, look at the numbers, and reverse-engineer to describe the action.
Other things are more 'real'. A bow attack, for example, uses one arrow per roll -- it cannot be described as an abstraction showing multiple attacks. If you grapple someone, you have him held. You have your arms (or whatever) around him. The move to grapple might be abstracted, but the final result is not -- he's either grrappled, or he isn't. A bull rush, or the rogue maneuver descrived earlier, is 'real', in that someone is really moved X squares..he's not subject to an abstract, unmapped 'positional defect'[1].
So while it's easy to imagine a three foot halfling managing to slice open a dragon's throat when the dragon leans down to snap at him (because there are no explicit rules for hit location, and size differences are calculated in armor class and damage), it's much harder to imagine that same halfling bull-rushing the dragon off a cliff without the use of 'magic' or special training'. (Working in size and strength modifiers to the check, I'm not sure even a 20th level fighter could do it to a CR 20 dragon, but I'm not sure...) The dragon 'really moves' -- he's now X squares away from where he was.
The manuevers in 4e are described in fairly explicit fashion, and their effects often involve moving or shifting targets. The strain of coming up with 'believable' (not necessarily 'realistic') descriptions for these manuevers might prove taxing for many groups, when you have to do it over and over and over, and not get repetitive or boring. ("So, the dragon tried to bite me and misjudged and tumbled tail-over-head 5 squares...again?")
We'll see. The problem is, D&D combat is very much NOT 'shift your brain in neutral'. It's detailed, complex, and tactical. It's a wonderful system. 4e looks to be every bit as crunchy. This means that you're constantly shifting between detailed resolution and abstract description, and the more barriers there are to making that shift, the less fun combat becomes.