Before we start another huge chain of people saying this is the death of Flash because all the developers will leave the platform due to revenue sharing, please read what the requirements actually are. This will only apply to very specific apps and developers. Unless you are planning to use Unity or UnrealEngine in Flash, this will most likely not apply to you.
This is not particularly enlightening. Any number of things are possible. It was possible for Adobe to institute unreasonable pricing terms before this announcement too.
EDIT: Uh-oh, somebody downvoted this. Quite worrisome, because right now it only applies to my comment, but tomorrow, it may not. Right? Because apparently one data point constitutes a trend.
They could have done it five years ago too. And you could shoot your grandmother tomorrow. We can play the "So-and-so could potentially do X" game forever. There is an almost infinite range of possibilities in the universe. Pointing out mere possibility is uninteresting at best and deceptive at worst.
