I bought a MacBook with Superdrive in August 06 and have wound up with exactly the same problem as many of the people replying to this post.
After just 7 months, and without any wear and tear on my part (I hardly ever carry my MacBook around; when I do, it's in its box and safely on the back seat of my car; and I don't even use the drive very much - I've probably only burnt 10 CDs, and downloaded 20 or so to iTunes), it just stopped working. It wasn't reading or writing CDs or DVDs, and I would usually have to restart the computer to be able to eject the CD.
I asked the people at Apple Care to let me downgrade to a Combodrive (as one other poster to this discussion has done), but no matter how much I tried to persuade them, there was no way they were going to let me.
The people at my local service centre were great, very friendly and helpful. They have replaced the Superdrive free of charge (I was still within my 1 year warranty), but of course, I am now resigned to the fact that the drive will go wrong again, and next time, it will be out of warranty, and I'll have to pay 3 or 400 pounds (6 or 700 dollars) to get another Superdrive.
My only option now seems to be to take out Apple Care cover, as it seems inevitable that the drive will have a very finite life span. This in itself will cost 200 pounds for 3 years, and I feel like I've been bullied into getting it, just because I was unfortunate enough to buy a fundamentally flawed product.
My advice to anyone thinking about buying a MacBook would therefore be: don't get the Superdrive!
MacBook Mac OS X (10.4.9)