Just like with the other poster - what type of introduction media do you want?
It can be anything. There is nothing special about it. It's just video and audio (if you want audio). It's the first thing that willplay when a DVD is put in.
You can make your own - or use your own video or not use one.
Those Sonic Foundry motion backgrounds or digital Juice jumpbacks work nicely for intros. Also if you are artistically challneged and lazy like me the templates in Premiere 6.5's titling app are useful.