I wouldn't risk it either. I have a few 8cm cd singles that i'd like to import in iTunes, but i guess i'd better create iso images on a machine with a tray-loading drive.
Not that it would be impossible for Apple to sell slotloading drives that accept 8cm discs... The Nintendo Wii for example, has no problem with Gamecube games, and all of them are on 8cm discs.