The one thing that traditional Flash applications have that Flex doesn’t is keyframes. Well no more. Flex 4 introduces Keyframe class that we can use to create animations from one keyframe to another to another. . .
Actually this isn’t anything hugely new. We could always animate from one property to another in a sequence which is pretty much all this dose. Keyframes just make it slightly easier and more intuitive.
Below is a simple explorer that lets you dynamically add keyframes to a motion path. When I say simple I really mean it. It just tweens the x/y values of the button. But it could just as well tween the z, or alpha, or any number of other properties.
Chet Haase has an excellent short video intro that you should watch on keyframe animation in Flex 4.