Lots of people are using flash as their animation package, for animating and then exporting png to other programs.
For Adobe not to pull out Flash from the market, as its use in web content has diminished, it has to be transformed it into a fully fledged animation software and not just a tool for flash content. This is one of the reasons they are expanding their toolkit in Flash, to make it a worthy competitor and alternative to other animation packages out there and make it feasable and cost effective for Adobe to keep it on the market.
What will this upgrade mean to C2/C3 customers? That depends wether C3 will have an animation system within itself, complete with a motion/animation graph editor. Nevertheless this will mean that Scirra customers will have at their disposal yet another animation package, from which they can export their animations to C2/C3.