Well, like I said--the term gets misused, a lot. It's not really a big deal, since the 100-word challenge still exists, and who really cares what you call it? I just always approach something labeled as a "drabble" with the knowledge that it may be anywhere from 100 to 1000 words long.

Anyway, it's still a shiny new word, so the definition is bound to be fairly fluid. It doesn't even appear in any dictionaries, to the best of my knowledge (Wiktionary nothwithstanding).