There is a fuse module for iso9660. Unfortunately, it looks like work stopped on it seven years ago, with its code left to moulder on sourceforge. The hardware driver itself would be a lot more difficult, as the atapi commands that cd/dvd drives require working in the chipset drivers. Plus, the hardware itself is not usually the culprit behind the crashes, so you'd not get much of a reliability boost from it, unless you're willing to have all of your hdd/ssd drive controllers be in userspace as well.