Either use Remote Disc or buy a USB SuperDrive. When you take a look and see how much space the SuperDrive + HDD take up in a MacBook Pro, you can see why we'd want them removed. It's 1/2 the laptop!
http://guide-images.ifixit.net/igi/FkpKKrqQlYsgNBq6.medium
95% of people would probably rather have a laptop that can get 12 hours battery life than the ability to install Adobe CS5 ONCE.
And I'm not calling for the death of optical media, but there's little reason it needs to be standard in all laptops when most people don't use it besides DVDs (again, external SuperDrive is available for them).