Nope, it's just a hole. I've been thinking of rigging up a lever so that I could use that hole to push the eject button. However, I only had to pop the cover once, and I'm 90% sure it was due to some wierd mounts I had setup, etc.

I don't know of anyone else who has setup a linux distribution on their central, so I doubt anyone else would need to open the cover to eject the disk.