I recently found a backup of an old Hive wallet (bitcoinkit.wallet), and couldn't figure out how to decrypt/export the private key using available software, so I wrote a small utility. I looked through the hive source a bit and saw it was using bitcoinj, so I did the same and it worked perfectly. I'm not sure if anyone else will find this useful, but I put the code up on github if there's anyone in a similar situation. My code only works on non-deterministic wallets with encrypted private keys, because that is what I had backed up.
https://github.com/JesseCorrington/bitcoinj-wallet-export
