Kim, I bet it's a breed thing but also dietary. I bet it will get better the longer he stays with you and gets healthier.
I have seen stuff in the pet stores that is an additive to the food that is supposed to really help the condition of a pets skin and fur. Something like that might help him out too. I did find a wonderful site that has lots of meds and vitamins pretty cheap if you want to check that out.
www.vetamerica.com I found a lot of their prices to be cheaper than some of the pet stores and you can get things there that you can't get at other places.
Good luck, and by the way, he is the most gorgeous "greasy" cat I've seen!