Disclaimer: no, I haven't reread Chapter 9 yet. I just remembered a few things I had wanted to mention.
Fourth edition seems a bit more combat-oriented than 3E did. Now, this might
just be my reading of things, but a few things contribute. The one that I like
the least is "roles." Every class fills one of four roles in combat:
controller (damage a lot of enemies at once; wizards), defender (front-line
combat; fighters), leaders (provide bonuses and healing; cleric), striker
(massive damage to single targets; rogue). This, I think, really helps to
propagate the "but our party needs a cleric!" mentality. The rules even say,
"if you don't have a cleric [role: leader]
I suppose the idea here is that by creating an assumption that a party is made up of one member of each role (and possibly an extra defender or striker, as those are the roles suggested for doubling up if possible) then writers of adventure modules can make assumptions about what kind of powers the party will have. I'm not sure if that's really useful for an module author, though. If you present a task or challenge, there should be more than one way to do it.
I also think that some classes have been made really weird by being crammed into this setup. Mostly, I'm thinking of the rogue class. Rogue now seems to mean ninja, rather than footpad or burglar. In fact, nearly all of a rogue's thiefly abilites are now summed up in a single skill (and remember that skills are just a binary has or has-not) called Thievery. His powers still include improved abilities to sneak and open locks, but those powers appear outnumbered (I have not counted) by powers that cause "vicious wounds" or "fierce attacks" or "glittering blades." I don't mind if there exists a class with "martial" powers that fulfills the "striker" role, but to me that is Assassin. I suppose that it's up to the players and DM to decide whether any given rogue is an assassin or a thief or, really, a ninja.
I'm not really upset or surprised to feel like D&D is drifting more toward optimization for combat. It's long been a fairly combatocentric game. I feel like its combat has gotten more complicated since 1E, though, while everything else has gotten simpler. I need to find a copy of the 1E core books and review the rules (if they exist) for flanking, cover, grappling, rushing, charging, crawling, and the like. I feel like they were one really simple, or didn't exist. I suppose having no rules for grappling is actually more complicated than having a rule, but as a DM, I feel like I'm expected to know all these moves, and if the player knows how a double-crawl works and I don't, I will look like a slacker.
Oh well. I'm hoping to greatly increase the amount of combat in my next RPG, so I guess I'll brush up on the rules and see how it goes.