Animated Boot logos can once again be acquired on the latest iOS jailbreaks using a tool from developer iH8sn0w simply called animate fix.
For example, if you're an iPhone 4S jailbreaker, all you have to do is download and install the animate fix package, select animated logo from the BootLogo settings panel, and restart your device.
This is a great way to add even more customization to your iDevice, as you can probably gauge from the screenshots and video...