For several years Coraid has posted a note at http://support.coraid.com/support/solaris/
" Users of ZFS should be aware that a bug exists in ZFS causing system crashes when a ZFS disk encounters persistent I/O errors. This bug has been verified using AoE targets as ZFS disks. Sun is aware of the problem and is said to be working on a solution."
I have wanted to use ZFS over AoE for a while now; perhaps the bugs have been fixed and we can now use it.