I know I keep making comparisons to Shadowrun, but that game's release history is a good model. First and second editions are nearly identical, with second edition being more akin to a 1.5 edition than a truly "new" edition. Third edition, however, featured a lot of mechanical tweaks and totally new artwork throughout.
There's a really insightful developer's note in the preface (or afterward) of Shadowrun 3e that says something to the effect of "when this game came out, it was competing with other rpgs; today, it has to compete with rpgs, video games, collectable card games, and the internet." The point was that the world had changed since the game was released and it had to adapt to those new market conditions if it wanted to survive. Similarly, when Earthdawn came out in 1994, it didn't have to compete with MMORPGs, Euro-board games, Xbox Live/PSN, freely available OGL games, iOS/Android games, and Netflix. In 2014, the game needs to do more to stand out and convince people to play Earthdawn instead of turning to those other options.
Of course, this was also the thinking behind 4th edition D&D and we all saw how the gaming community reacted to that one.
I didn't say it was a path without risk!