Some of my fellow developers are awesome... Yes, not all!
Anyway i am going to try something a little different in A Shooter, that is to put in a sprite from other devs upcoming games. Presuming they want this. So..
Get a sprite from their upcoming title, Place it into my game somewhere. my example is a bee from an upcoming shooter, place it into a couple of levels as a simple collectable.
Then put a special section into my credits page. Something like, 'Special Appearances', 'Bee from upcomingshooter'
This sounds cool to me, not sure if it can generate any hype, but one never knows.