Namely that Rand will kill Graendal in TGS. But since this wasn't unexpected and I still didn't know, how Rand will do it, it wasn't that annoying. And when this confrontation came, I had still never expected that Rand - even being cuendillar hard - would just balefire Graendal's lair.

I'm afraid, though, that as soon as it will be revealed who killed Asmo, one will somehow learn of this before reading ToM or AMoL, because those who know it beforehand will burst to give it away or at least give away that the answer is in the respective book. For this reason, I was also certain that Asmo's killer wouldn't be revealed in TGS. Otherwise one had at least heard that it will be revealed, after the first people got TGS to review it.