Ok, my thoughts:
1) Has anyone mentioned that Shadowthrone, Edgewalker, and the third dude (who I don't think is Hood) don't seem to be able to see the dead man and woman? It's a bit like how in one of the other books Cotillion realises that there are loads of things in Shadow which he (and presumably Shadowthrone) can't see, though others, like the Hounds and Panek could.
2) The fighting dogs definitely seem to be signifying something to me, though unknown as yet. A bit like the Nachts with Withal on the Crippled God's isle in MIdnight Tides.
3) Kruppe's 'witness' suggests two things to me:
a) Karsa will play an extremely pivotal role in whatever happens...and possibly his last.

It also sounds like the events have already happened, i.e. Kruppe is about to recount the events of Toll the Hounds - like Trull was supposedly doing for Midnight Tides. This lends credence to Kruppe being the narrative voice. This in turn suggests to me that unlike with Midnight Tides, where scenes of Trull telling the story where never mentioned, we may in this book get scenes, like intervals, throughout Toll the Hounds with Kruppe, K'rul, and the third guy briefly discussing what Kruppe has just told them. Possibly.