First, there was a great post by ... [MENTION=22779]Hussar[/MENTION], I think? ... in a recent thread wherein he laid out why he thought the 2E->3E change was bigger than the 3E->4E change (IIRC, focusing on the fact that someone who knows 3E can pick up a 4E character sheet and play pretty effectively, while someone who knows 2E will not understand most of the 3E sheet).
1. Base Attack Bonus that led into multiple attacks.
BAB is 3.XE only, and in editions prior to 3E multiple attacks came from being a Fighter and from Weapon Specialization points - not your THAC0.
2. Hit points as the sole control for health.
Except for poison damage pre-3E, which killed instantaneously. Also, in 3E, you can take Con damage which can kill you without reducing your HP to 0. (EDIT: Forgot level drain killing you, too. Thanks, [MENTION=87792]Neonchameleon[/MENTION]!)
3. Wizards had nine spell levels and a goodly number of spells per level.
I don't think Wizards had 9 spell levels in the Rules Cyclopedia, but I could be wrong. Also, conspicuosly absent from your list is how many spell levels Clerics and Druids had ...
4. Your defense against a spell was a saving throw. (Minor point for me but true)
Except for all those spells that required attack rolls.
5. Utility magic was part of the spell selection process and not a ritual.
6. Utility magic came at lower levels and was decent.
I'm not 100% sure how to parse this one.
7. Named spells like Tensers floating disc.
Exist in 4E.
8. The Great Wheel Cosmology
Doesn't exist in Dark Sun, or Eberron, or the Forgotten Realms, or Dragonlance, or Birthright, or ...
Do not exist in Basic / Rules Cyclopedia, which just has 3 (Law, Neutral, Chaos).
... Sometimes, I guess? I mean, this varied really, really heavily depending on the group. And, I guess there was the occasional magic item that required a given aligment, but this is not something that is universally true among pre-4E D&D (especially given the large number of DMs I've run into who just ignore the whole thing anyway).
11. Only magic healed instantly.
Sure. Still true in 4E, if you're talking about things like actual wounds or diseases. HP, since the Gygaxian days, is not purely wounds, so IMO, 4E's the first one to get this right.
12. Mundane healing was measured in days.
... Except when it was measured in weeks or months. Which, actually, almost never happened, because you nearly always had a cleric (either PC or NPC) with you, anyway, so mundane healing was almost completely replaced by magical healing, anyway.
13. Spells could be disrupted. (Although by 3e this was all but dead I agree).
You can disrupt spells in 4E, too, so ... ?
14. Magic items didn't require personal energy (surges) to use.
Except for the ones that took HP to use. And making magic items took personal energy / health in previous editions (Con drain in ... 2E?, XP in 3E).
15. Spells outcomes were based upon both the text and the stat block.
Still true, so ... ?
Also, did you never have anyone describe their spell in their own way before 4E?
16. Every class didn't have "powers" and was not AEDU.
Sure. But in 1E, not every class had "Skills" (just the thief), and in 3E, they did.
17. The game was not heavily dependent on a grid. (even if houserulable 4e wasn't made for theatre of the mind play. 3e started down the path to grid though I agree.).
But with everything measured in inches, it was (purportedly) dependent on being run on a tabletop. If you can ignore one, you can ignore the other.
Also, if 3E was heavily dependent on a grid (and I agree it was), then this doesn't belong in your list.
Also, 4E gives a good way to resolve minor combat encounters: run them as skill challenges! No grid at all!
18. Magic Resistance/Spell Resistance existed.
True enough.
19. Classes were not shoehorned into roles even if many players chose a role for their PC.
Classes were expected to fill those roles, however - if you were playing a Fighter, it was expected that you would be holding the line and protecting the wizard from the badguys (or the wizard died and the player was unhappy with you). I mean, Fighters were called "tanks" long before WoW showed up. Similarly, if you were playing a Cleric, you were going to be doing some healing.
All 4E did was take the roles that had been assigned to those classes since time immemorial, make it explicit. It was, in no way, "shoehorning."
20. Level drain existed (although again in 3e they were already going the wrong way).
So, again, not something that existed and was unchanged pre-4E.
Also, I have always, always, always, always
hated level drain. It's fine when you're playing with throw-away characters, but as part of a long-term campaign it's one of the stupidest rules I can think of.