Yes, as reply #2 stated, you can "UN-fuse" a fusion drive setup using Terminal.
HOWEVER -
Be aware that if you boot from the recovery partition, and then launch Disk Utility, it will automatically attempt to "repair" the two separate drives back into a fused drive!
I'm not sure if this can be "over-ridden" so that you can then use Disk Utility as you wish on the separated drives.
Does anyone have that answer yet?