I've spent the past few days looking up Java window transitions that work with Swing components & containers (JFrame, JPanel, etc.).
Yes, there are packages such as JavaFX which includes a Timeline & Transition framework. I also came across these:
Trident: Project Kenai — We're More Than Just a Forge
FRC: Filthy Rich Clients (find the Animation jar (org.jdesktop.animation))
However, I've been impatient lately