Had my game yesterday. I won the game pretty solidly and I wanted to share a few takeaways:
Having a plague priest is awesome. It's like having the possibility of an extra blades of putrefaction on hand (picking curse of course) with a better cast value. And his mortal wound pings is solid in a list that does a lot of that all ready (wheel, spells, blessed sons explosion, blightkings aura, tree, plague monks). In my game I used the plague priests longer move with a guaranteed 6" run (he was in a Vanguard) to summon plaguebearers in the opposite end of the map.
Blightkings are still good without the blight cyst. It is more about the weight of dice than before but they do work. Also the unit champion having 5w (counting as 2 models) did have an impact. And sticking most of them in a Hunters of the Heartlands battallion helped (no monstrous rampage against them)
Blades of putrefaction still having the old wording goes great with all with attack. Used it on the warriors this game. Would be insane on the plague monks.
Chaos warriors are fantastic with the new faq. Permanent +1 to save when 10+ models (occular visions after 10) makes them extremely durable.
Harbinger of decay will have his aura up permanently. With the added command points and heroic actions it is always on and the aura works on all your non-skaven models (they are not mortal)
Using Rally on the last member of a 10 man blightkings unit feels like cheating
Having not a single monster in the list while still having the opportunity to ghetto-monster with the new spell is great. Denies a lot of WPs for your opponent.
Having to stick the tree in your own deployment felt bad at first but it did mean that at no point in the game did I lose out on contagion points.
Those are the thoughts of the top of my head. Hope it helps.