Apple isn't about choice - they know what you need - and so shall it be.
Whereas many high-end Windows laptops offer you the choice to stick in that bay what you will: optical media, extra hard drive, extra battery (see ThinkPad). All those complaining about the disappearing express card slot should be pissing and moaning about the inflexibility to swap out the optical drive as well.
Which is probably good. My psychologist say that too many choices isn't good. I don't give my son that many choices because he just becomes deadlocked.
The problem with swappable media bays is cost of the accessories and hey affect how small you can make the laptop.
Apple will make the decision eventually to yank the optical drives and people will piss and moan about it and then open their eyes and see the plethora of file sharing options that they never bothered to learn.
I heard the same "is Apple crazy" when they nixed the floppy from the original iMac. At that time people were yammering about how Zip drives were going to be the next file interchange format (much like the yammering about Blu-ray today)
external optical drivers are but a mere inconvenience. They don't prevent you from accomplishing your goals but the truth is a 3Ghz Intel mobile chip easts up 35 watts of power max. The next quad core Clarksfield chips coming will be 45 watts max. Apple's got to find a way to deal with another 10 watts and frankly the optical drive is probably gonna go and you can "really" forget about Blu-ray as those drives are even hotter.