Jack,
We have not attempted any such port and, as I understand it, Titan is not going anywhere at this point.
However, what would you gain by this? We already support the various APIs with native evaluation against BlazeGraph and it is significantly faster than Titan on a fraction of the hardware. The general problem that key-value store architectures face for graphs is that they do not have good locality for traversal. This means that you can easily load data into them (this can be an embarrassingly parallel operation if you do not use a global dictionary encoding) but that traversal and query performance are severely handicapped. To fix this you either need to allow the query to flow over the data (as we do with BlazeGraph) or you need to use a completely different architecture (as we do with MapGraph).
Thanks,
Bryan