Threefish is actually a tweakable block cipher - it takes a 128-bit tweak in addition to the key and the input, so it should be well suited for disk encryption.

Threefish is actually a tweakable block cipher - it takes a 128-bit tweak in addition to the key and the input, so it should be well suited for disk encryption. It's a bit disappointing that it hasn't seen more uptake since the SHA-3 competition. I think the tweakability and large block size makes it a more flexible primitive that AES, and even naive implementations should be constant-time. It's hard to compete with hardware-accelerated AES, though.