A brief update in Rich Baker's blog: he's working on the Monster Manual, specifically writing what he calls "mission statements" for various monsters. That includes guidelines to "help the DM with target designation" for monsters (like attacking the nearest enemy, or attacking whomever damaged it the most). Baker is also working on morale notes for monsters -- which "are likely to run away when they're hurt, and which are fanatical or bloodthirsty enough to fight to the death."
One of my pet peeves of D&D is the complexity of high level play. High challenge rating (CR) monsters can have several pages of description that the DM has to manage. Players often win because the DM forgot the dragon was immune to cold iron or spells starting with the letter "M." It's often player success through management failure. There's just too much information to manage.
Worse, most players desire high level play, while most DM's loathe it. Because of this, we have a constant battle of players against DM, where the player is striving for the higher levels and more experience and the DM prolongs the low-level manageability of the game. Third edition had a mid-level "sweet spot," while fourth edition designers have vowed to make every level sweet.
A mission statement for monsters not only gives the DM guidance on how the monster fights, but it makes it more logical that the monster is there at all. Tactics are critical as well. The example given at Enworld was the beholder. It's a monster that has three main attacks: bite (lame), anti-magic (powerful), and various ray attacks (extremely powerful). How do you know when to use each? DM's are confused. Players usually just run away, mostly because the thing is too dangerous and unpredictable (no defined tactics). It's a swirling ball of doom.
There is the argument that these defined tactics and purposes takes some of the choice out of the game. We get back to the complaint that D&D 4 sounds like a video game. If being like a video game means 4.0 is logical and systematic, I'm all for it. Not only does it help existing players, but it will inevitably bring new ones to the hobby.
Role-playing is such a subjective hodge-podge, that it turns a lot of people off, including other gamers. There are many miniature gamers and board gamers who look askance at RPG's because they seem illogical, subjective, soft, as if we make the rules up as we go along. If we can at least make the combat more systematic, I think the game will attract more players, maybe even the millions of World of Warcraft players, whose only gaming experience has been their predictable online world.
A more systematic game will also reduce prep time for beleaguered DM's. My observation is this: DM's are very bright. Being a DM takes management skills and resources to purchase the majority of gaming material. Such a person is capable, and capable people end up with things like good jobs, families, and community responsibilities. They are the exact people likely to quit gaming and bring down their group with them. Make their job easier, and you preserve the game by preserving gaming groups. As a DM, before I had a family, I used to put in 1 hour of prep time for every 2 hours of play, or if I was bored, maybe 1:1. Now it's something like 1:4. Make the DM's job easier to prepare for the game and we'll have more games.