In d20 Call of Cthulhu, every character is effectively an Expert, and the Expert class is flexible enough to cover just about any noncombatant without magical powers. Even if you provided D&D's full list of classes, just about any normal person would be an Expert -- except that they should get an extra Hit Die, better BAB, etc. for finishing up a PhD thesis.1. character classes (Characters are all skill-based.)
A few would be Fighters though (or something close to the Fighter), and that Class would work better for a few key character concepts -- especially for experienced adventurers.
They're not as important in a game without plentiful, armed, melee combat.2. attacks of opportunity
You can have a unified spell list or many, many fragmented spell lists without the Arcane/Divine split of D&D.3. a division between arcane and divine spells (There's a single, unified spell list.)
Alignment has a place in a game with supernatural forces representing Good and Evil or Law and Chaos, so it has some place in a fantasy game, if only so you know which team you're on. Having both a Good-Evil and a Law-Chaos axis though, that's just weird.4. alignment

Most of those changes seem very specific to Call of Cthulhu in a modern setting. Granted, you can play D&D with those changes, but I don't see 4th Edition going in that direction.Could this be a foretaste of 4th edition?