Cents have a pretty small profit margin for the Mint as it is, so I imagine that's part of it. I wouldn't be surprised to see cent rolls made available in 2009, if they come out with a new design.
The only place I can find dime rolls is Starbucks. But you can only get 1 or 2 rolls. If you have a friend who works at Starbucks they may be able to hook you up.
If they change the designs, especially if they do so as part of a series like the quarters or nickels, they will start selling them. If we get the four designs for the cent in 2009, you cn bet they will sell rolls and bags to collectors.