I think I disagree with the premise that the players have to understand a whole lot of rules to play and enjoy 3E. There is a guy who we knew from years ago who just recently moved back into our area and we invited him to play with us. He never played RPG's much (he sat in for a session or two in our old Rolemaster games) and he had never touched 3E before three sessions ago. He's doing fine.
I think if a player comes in saying, "Well, I need to know every rule that could apply to any character I might ever want to play including all the feats and every possible Prestige Class that I might want to shoot for. Until then I can't make a character." then hell yeah they've got a lot of rules to swallow. But if they think of the character first and then somebody experienced helps them emulate that PC as best they can within the rules then they start the game with a limited set of rules they must understand.
Our newbie guy said, "I think I'd like to be a Human Barbarian. I want to hit stuff hard with my big weapon." No problem. He's had to learn the general movement and attack rules, how you make skill rolls, the rules for Rage and that's about it. The toughest concepts he's really had to master have been Charging, Flanking and AoO's. Honestly he seems to have grasped the why's and when's of AoO's better than some of my "veteran" players.
The important part is that I have a good grasp of the rules as the GM. I know how Grappling and Tripping and Attacking an Attended Object work so when a player says, "I want to knock down the Evil Wizard, jump on top of him, pull the wand out of his hand and punch him in the face!" then I can say, "Ok first you need to make a Trip attempt. Now he's unarmed so he doesn't threaten an area right now..."
With all of that said, I have no quarrel with folks who want a more "rules lite, adjudication heavy" system. I know that BU has read my Samantha the Red Story Hour. That's as "rules lite, adjudication heavy" as it is possible to get (I think). It is fine to want something closer to that end of the spectrum. But I don't know that having it be the default system supported as D&D is a great marketing idea.
I think that the more you move toward a "rules lite, adjudication heavy" system the more you require that a group has a great DM in order to have a great game. Not every group is so blessed and if the DM has to make 50 judgement calls a session instead of 5 then he's setting himself up for a lot more potential hurt feelings or the sense that the players are pushing him around.
The stance that I've adopted is that the rules are there as a guideline for me, but not a rigid one. Last session we had a situation where an enemy combatant had climbed atop a low hut and was being attacked by a PC with a spiked chain. Another player asked, "Do I take the -4 for Firing Into Melee even though she's 8 feet off the ground and ten feet from the Psi-Warrior who threatens her?" The rules say yes but those sound like reasonable grounds on which to bend them. I ruled, "I'll split the difference with you and make it a -2."
That's what I want from a rules system. Guidelines that I can look at and then bend or break as the circumstances dictate.