I was thinking about a deck like this as well, and at first looking at your list i wasn't so sure about the stoneweaving, till I considered that at low mana there are very few landmarks so if you cast this on turn 2, it guarantees (atleast for now untill they add more  landmarks) you a frozen thrall which is great for consistency. 

I'm not entirely sure how I feel about ancient preparations yet because I don't exactly know how good predict is. It might well be nuts especially for a deck like this if you can consistently get your thralls or taliyah combos on turn 6 or 7. 

I think Lissandra will be able to level up alright in this deck, with taliyah and ancient hourglass cheating out extra summons of her thralls, but I think the Watcher will probably take too long to be a factor most of the time with this list.  

It'll be kinda neat how in their levelled forms, Taliyah will be the offense and lissandra the defense, anyways can't wait for the 3rd to see if this archtype turns out to be decent. Lissandra seems to pair so perfectly with trundle that it's nice to see and think about how she might pair with other champs.