If I may be so bold, I think this is a rather silly discussion and some of you seem to be arguing at cross purposes...
For example, the cited examples of the floppy disk and USB memory stick have come up as external drives that can result in corrupted data if removed while in use. However I have never, ever in my many years of computer use ever come across a computer - of any type and any operating system - which can prevent the user from removing a floppy disc or USB memory stick while it is being used. That goes for PCs, windows, LINUX, Macs, C64s... not one. In the case of USB sticks, I frankly cannot even think of any way in which the operating system could prevent this.
What some OS's do is warn the user not to do this, and facilitate correct procedure including unmounting of the device prior to removal. Windows in one such OS that does this, with the "Safely Remove Hardware" device which appears in the task tray whenever you insert a USB stick or external hard drive or similar. Now if I want to protect my data I know to unmount it first, however if I want to I can just pull the damn thing out. I'm not as familiar with Mac OS, but I suspect it's a similar story - I do know for certain that you can just yank a USB stick out of a Mac if you wish, and there's nothing the Mac can do to stop you.
In this regard I see absolutely no difference whatsoever between the various operating systems.
So I don't know why anyone brought up anything other than CDs, because frankly they seem to be irrelevant.
As for CDs... there seems to be a bit of crossing over of distinctions here. "Mac" (or "Apple") and "PC" are often used to describe both distinct hardware, and distinct operating systems. This becomes problematic when take into account that the operating system and hardware are not necessarily mutual - I can run Mac OS on PC hardware and I can run Windows on Apple hardware. It becomes even more problematic when you introduce a third operating system which can be used on both types of hardware. And finally it becomes even more problematic when you are discussing a problem that's potentially a combination of hardware and software - ejecting a CD.
The problem with some Macs in this situation is that hardware and software have been linked together in such a way that they're functionally one in the same. So you don't have an eject button on your hardware - the physical drive - but only software ejection capabilities (using a designated key on the keyboard still constitutes a software ejection).
This is all well and good when everything is going well, but it's problematic when something goes wrong and you need to physically override the software.
The question really is whether you should have a hardware eject function which is entirely independent of your software or not. I'm inclined to think you should, because I'm inclined to believe that software is not 100% faultless.
The next question is of course what form that hardware eject should take. One option is the pin-hole eject found on many drives. Another option is to have a standard eject button. The pinhole is a pain, because, well, you need to go find yourself a pin to use it. But in saying that it has the advantage of better protecting your data because you can't accidentally bump the button while you're in the middle of writing a CD or something.
