Thing is, there isn't even a clear and shared understanding of what Godwin's Law means. According to wiikpedia, the Law states...
"As an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches 1
All well and good. But then, you see cases where someone who mentions Hitler gets accused of BREAKING Godwin's Law, as if the law were an imperative along the lines of "Don't mention Hitler in a discussion." Whereas, insofar as Godwin's Law is a predictive statement, it would be broken by having NO ONE on the thread mention Hitler.
Be that as it may, getting rid of Godwin's Law would be a no-brainer, as already exemplified by numerous posts on this thread(ie. a world where there is no Hitler, and/or no Godwin, or Godwin never decides to formulate the law).
I guess a bigger challenge would be to come up with a scenario where the Law is well on the way to being formulated and presented to the world, but something intervenes to stop it, or to thwart its spread. Maybe, for some reason, mention of Hitler in unrelated topics becomes extremely taboo, and so the phenomenon described by the law ceases to exist.
So, let's say, some time in the early 90s, some netizen gets compared to Hitler in a debate, goes over the edge because of this, and walks over to his local coffee shop with a sem-automatic and shoots the place up. The media goes into moral-panic mode, with headlines like "NAZI COMPARISONS: ONE STEP TOO FAR?", thus leading to an unofficial but generally observed moratorium on them for a few years, thus making further publicization of Godwin's Law a moot point.
Of course, the moratorium will eventually end(like, for example, the post-911 "Death Of Irony"), but by that time, the momentum for spreading the Law has been lost.