I made the bootanimation for 480x854 devices. I wasn't sure if the animation should be either portrait or landscape, so I choose the easy way and made it portrait. Please try it out and report back if it works...
The bootanimation didn't work, stayed black. I replaced the original bootanimation.zip which was already there with yours. I used the Bootanimation Utility Lite from Android Market which worked but didn't had right resolution so it didn't fill the whole screen. I attached the bootanimation which worked BUT with wrong resolution.