Reynard said:I figure the ultimate litmus test of whether an edition can be considered "still D&D" or not relates directly to whether a group can continue to play in their preferred "vanilla plus toppings" homebrew campaign setting or not. There are folks that have playing in the same world across decades and multiple editions. If 4E suddenly makes it impossible to continue to do so (without huge amounts of works or waiting 3 years for supplements) it fails the test.
Unfortunately, pretty much every edition of D&D fails that test.
oD&D -> AD&D is the only one that really qualifies.
BECM D&D goes on a really divergent path.
AD&D 1E->2E removes half-orcs, assassins, monks, demons, did weird things to the Ranger, etc.
AD&D 2E->D&D 3E had vastly different interpretations of various classes and races...
Cheers!