The Superdrive is worth the extra money. Believe me.
I was going to buy the base model, but at the end I got the black MB (not for the superdrive, I thought that I would never use it). But now I realize how helpful is to burn DVD's in the laptop and not having to go trough the problems of passing it to your PC or another Mac.
Are you in the habit of burning DVDs? I've used at least a couple of computers with DVD burners (one Mac, one PC), and I rarely if ever used the DVD burner. So when it came time to buy a MacBook, I bought the lowest-end modeld without SuperDrive. In 6 months of owning the MacBook I've never once burned a DVD or even a CD.