Yes, this is common. I believe there is another thread here in the Zl1 forum about it.
I had it noted to the dealer. My looks like yours, with even less miles. We agreed that it would not make sense to change out the seat covers at this juncture, as it will likely get worse or happen again. My plan is to see if GM comes up with a solution, and if not, work with my dealer for a seat cover repair/replacement before warranty is up (or if it gets really bad).
EDIT: Here is one of the previous threads:
http://www.camaro5.com/forums/showthread.php?t=404062