Ancalagon
Dusty Dragon
Here's an interesting D&D That Never Was: a version of 3e that was built on what I disparagingly call the "2.8e" books- Skills & Powers, Combat & Tactics, Spells & Magic, and High-Level Campaigns. But to be clear, the thing I am disparaging is exactly what I am postulating to be the central feature of this version of 3e- the extreme customization, with subabilities, modular class building, etc. A version of 3e far more finicky than what we got, with poor attention to balance, but with lots of cool tactical combat rules, and possibly utilizing some form of spell point system. Because of its modularity, we never get a sorcerer, and this 3e doesn't need a separate barbarian class (or ranger or paladin). Instead, the options for building one of the "Big 4" cover almost all your possible options, with druid, monk, and bard as likely additional class chassis.
That's quite a plausible proposition. In fact, I was a bit surprised that did not happen - at least not until I grasped the "unified d20 roll" core of 3.0, and then I understood.