I think what gave it away to me was re-reading the Sword fo Shannara after having read the Word and Void series. At some point Allanon is talking to Shea about power, and he mentions the power of the Word. No mention of the void, but it jumped out at me.
I'm really pleased they are connected and that we will see Terry's vision of the transformation the world will go through. I loved Armageddons Children and look forward to the next book
