I’ve had sufficient comments and time on my hands to play a little with this opening slide for most of my presentations.
I altered the video’s outline to be less “ripped”, made it tumble rather than pop out of the book, and gave it a landing “splash” using the Anvil build (can you work out how I did that?) What do you prefer – the original, or this modification?
Les Posen's Presentation Magic 
Les, I like the new version better.
Yes, I was able to reproduce the anvil effect of the dust flying without seeing the object drop by making a second copy of the object, giving it an opacity of 0%, and assigning the anvil transition to it. Very clever, and thanks for the idea!
I did it simply by introducing a shape with a square bottom (just a rectangular) and then making it transparent, as you suggested. The tumbling effect is something all keen Keynote users should master as it has multiple applications, eg. CD or DVD rolling on or off the slide.