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.
Reynard said:
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.
I'm one of those people, while I do quite a few short one-off campaigns and even jaunt into other systems occasionally most of the games I both play and DM are set in a homebrew more than twenty years old that I took over from my older brother and continued using to this day. Quite simply put if I can't convert this homebrew into a system then it can't be my primary system. I could still run a few now and then but for the vast majority of what my group is invested in it just wouldn't do. I liked Exalted for all that it has its own problems as a system, both to play and to GM. When I realized it's own setting was too embedded in the mechanics for me to rip out and throw in my own material on that scale without massive problems that was it. The uniqueness of D&D and in my opinion the factor that has kept it at the top where so many other RPGs have fallen out of print is adaptability. Surveys invariably report that more than half of all groups run homebrewed settings or extensively house rule. The ability to handle these sort of wild hodgepodges that break other systems down or require extensive work to shoehorn in is what makes it D&D, not any particular flavor of the implied setting. And the further away from that it steps the more it imperils its own continuity as a game.
