Intruder Alarm has to be around the top of the most combo-enabling cards. It is the engine for so many decks. I used to use it to untap big blue ETB tapped creatures, but with Kiki-Jiki, Mirror Breaker, infinite haste is just too fun when you can pull it off.
Some good playable pulls, and a great box topper! Hopefully you got some cool dragons as well.