Old news is no news
Dancey cites his 500+ page marketing research study that was used to engineer 3e D&D in describing gamer preferences - this study looked at 2e gamer prefs, however. The landscape has certainly changed since that time, and 1.5 D&D editions and a plethora of d20 games later I don't know how valid those conclusions are anymore. For example, some gamers have no experience except with 3e/d20: how does this influence their concept of complexity or rules lightness/bloat? Do the same 2e gamers believe that 3e/d20 makes their gaming better?
Applying conclusions based on old data gathered using an out-of-date product to the current crop of gamers is of questionable value, IMHO.
(And where can I get a look at that study, anyway?)
Player options, GM headaches
Dancey describes the emphasis on providing players with concrete options - "if I do this and this and this, I want to know exactly what the modifiers will be without depending on the GM." All well and good, as far as it goes. In theory it should make the GM's job easier - everything is spelled out. In practice however, that may not always be the case - the increase in complexity in front of the screen, for players who have to manage one character sheet, is compounded exponentially behind the screen for the poor GM. Some GMs make up their monster and NPC modifiers on the fly as a result, which to some degree negates any advantage that was gained by putting more control over modifiers in the players' hands in the first place - GM fiat is still alive and well, largely as a result of trying to give the players more control over the game. This is without recourse the usual, overt means of GMs hosing players - encounters that are too powerful, nerfing character abilities, and so on.
An inexperienced or overworked or 'power-mongering' GM has just as much ability to be a prick in the current iteration of the game as in the past - this is an illusory improvement.
S/he's called Game Master for a reason
Along similar lines, the idea that putting more control of the game in the players' hands indirectly suggests that some of the problems with 2e were related to poor, or at least inconsistent, GMing. Where was the help for GMs in this?
The very intelligent suggestion given already is that there needs to be a comparable, current, rigorous study of GMing and ways to make the GM's role easier and better.
Chicken or egg? Not in this case
Finally, to wrap-up the topic of making 3e/d20 player-centric, engineering a game that rewards players without a commensurate reward for the GM is a potential disincentive for gamers to step behind the screen, and for those that do to stick with it and develop better GMing skills. One might argue that this is a chicken-and-egg proposition: without a GM, the players cannot play, but without players, neither can the GM. However, many of the things that make GMing enjoyable have nothing to do with the players directly: designing new monsters, writing deep game-world backgrounds, creating interesting NPCs and so on are for many GMs a reward in itself. Ultimately GMs who cannot find players may still find game-related activities to be enjoyable - for players this is perhaps not as true. This would be another aspect of gamer behavior that needs structured study.
Proposed for analysis: The game does not exist without the work of the GM - a system that makes the GMs job easier rather than harder is more likely to result in happier GMs and more and happier players than one that doesn't.
Rewarding rules-mastery, or adventure-mastery?
One of the stated goals of 3e was to reward 'mastery' of the game system, like M:tG - according to Dancey, as this was one of the conclusions in the old study of gamer prefs. The questions I have are, (1) at what point do additions to the system become complexity of the sake of complexity?, and (2) at what point does the game cease to be about the adventure and become about the game itself?
My friends and I, way back in the day, used to play a lot of Squad Leader, and as new modules were released we gobbled them up the way fat kids eat Little Debbies Cream Cakes. Eventually we reached a point however where we spent more time figuring out what rules applied to a particular maneuver than we did maneuvering our troops and tanks over the hexagons. The game stopped being fun for us about the same time - we exceeded our collective threshold for exactitude. We didn't play SL to master the rules: we played to experience the vicarious thrill of the company commander on the field of battle.
'Complexity' in the game, and reward of rules-mastery, may have been a stated preference, but does 3e/d20 meet this preference, or exceed it? If the latter, at what point does this occur? What is the break-point where rules-mastery diminishes adventure-mastery?
Finally, I have to take exception to the RD apologists: the "desperation" comment was pejorative toward a lot of gamers that have well-reasoned motivations and practical experience for opting for rules-light games. Some of his comments in this thread have only served to reinforce this.