Interesting thing that just occurred to me. The first place we ever heard of the One Dream was from Acer Magnum Malus, the Trow who talked to Antero's student Ewan. He said that Connacht was merciful on them, and instead of "returning [them] to the One Dream", he imprisone them beneath Rhi'anon. From this, I figured that the One Dream was some sort of "other side", the spirit realm, and that when one dies one is returned to it.
But now we know that the One Dream is the source of Wyrd's power, where he first saw the world and got his inspiration. And that it has since been shattered into 49 Dreams of Wyrd.
So... when were the Trow in the One Dream, what were they doing there, and how could Connacht return them to it? Was it still around in Connacht's time, and just recently shattered?