It would be a great feature, but obviously adds complexity. You can get half way there with single disk ZFS, which lets you store multiple copies. But the key feature is that files and directory info are checksummed, and regularly checked, so corruption cannot silently occur. But I think that usually the whole disk is lost, rather than getting bad blocks (so 90's).

For any archival DVDs I burn, I compress, then run through PAR2 http://en.m.wikipedia.org/wiki/Parchive