Can you describe your need more? There are no laptop drives of this capacity I am aware of at the moment - are you wanting to do full disk encryption on workstations?
I don't know of any plans to support this in the v5 product range at the moment, simply because no one has expressed an interest in it. You may indeed be the first!
We have several offline machines (v5) that we are planning to replace the second HD with the Western Digital’s 2.4TB and 3TB internal drives. We are not going to be able to break these up into smaller partitions. Our need is to encrypt the entire drive along with the C drive.