Acutally... the HDD is not only Encrypted but the partitioning system is also propritory..
And no its not based of RieserFS. If you read the forum completely you'll relaise the user had actually not formatted a previous ReiserFS partition of his HDD and hence wehn he initiallized the HDD in his PS3 and analysed it later he thought the partioning scheme is like ReiserFS. However, once he formatted it it was back to the way it was.. "unknown
"
But i have faith in our Devs and they are working on it. So we should see soemthing soon.