heat shield insulation torn off?

[kevinf2090]

A few days ago i was looking under my car, i saw some kind of silver paper torn off with foam inside. I was told that it could be the insulation at the bottom of the car. I this something that should be repair immediately or can it wait? How much would a typical dealer charge for this repair? It's a 2007 mazda3 w/28000 miles.

here's a pic of it(http://img696.imageshack.us/img696/5142/06302010175.jpg)