The post from 
Ones we already saw
I agreed with a lot of people's takes on these, so I want add much. I'm really intrigued by the Avalanche Walker, though. Before 6 mana it's always on curve. A 3 mana 3/4, a 4 mana 4/5, or a 5 mana 5/6. It also has backline, so it's always better than vanilla. Not only that, but you can play a spell first if you need to and still play this. It's the flexibility of Empower turned up to 11. I really like it. Magic needs some really powerful creatures to get a creature-based deck off the ground. This is a step in that direction.
New Cards
Spirit Storm
One of those cards that will give the balance team nightmares. It also severely limits design space moving forward (and forever if they are serious about not rotating sets). One positive thing to say about this card: it rewards creature-based decks that focus on the board. That is the opposite of both Anubians and BWD. Zombie decks also won't run this because they don't run many afterlife cards.
That means this card can push new archetypes. We'll just have to see if it pushes them too far.
Pallas' Wanderwagon
Heavily overstatted at 4 mana with a fun mechanic. I think it will marginally raise the skill cap/expression for magic. Something like a tempo magic deck (related to CDM) can probably run this to great effect. Swap to 6/3, go face, then swap it back to 3/6. Another card pushing Magic towards creatures.
The Reinnapper
Meh. Some utility to get rid of buffed Marsh Walkers and the like. It's neutral, so maybe someone figures out a nice fit for it. It does compliment The Dearly Departed (if it survives a turn), but...meh.
Thawed Heart
Great card. Void hate with a strong heal synergy making it valuable even when facing non-void-based decks. Pyramid Warden stock continues to rise as void removal becomes more prevalent.
Woodcutter Imp
What an interesting card! Overstatted but with a negative side effect to (maybe) make it balanced. Important to remember that your opponent takes their face damage first. This little guy could single-handedly make hand-buff war viable. Pull him with OOIM, buff him up, then surprise for 10 damage to the face. Using it to trade will be very costly.
Overall, a really nice way for War to use health as a resource similar to Death.
Take the Reins
This may be a failure of my imagination or skill at GU, but I can't see running this card. The mana cost is too high and the conditions too strong. If you have an empty board, can you even play it? If you have a board, do you need to play it? Spending 7 mana to take a creature for one turn is a hard sell.
Winter's Bounty
So control nature is getting some love. Two of these and 2x Compost Charms is 60 points of healing. There aren't enough Flame of Second Shatterings or Pyrrhics that can handle that much. Running this card basically forces your opponent to beat you with the board. It will be interesting trying to decide to run 1x or 2x. Is the second one really worth it? 6 mana for 20 HP compared to 2 mana for 10 hp from Compost Charm.
Nature also has random card generation, so randomly seeing this in aggro decks is going to be...fun.
Candy Chain
Hard to talk power level until we know what Candy Links do, but this is an interesting card. Deception doesn't really have worthwhile relics outside of Makeshift Shiv. This might give midrange/control deception a relic they want to play.
Summary
Overall, I like the cards. They appear to be targeted to bring out new deck archetypes rather than strengthening existing ones. There are some cool ideas for sure. The big questions are about how these will be distributed, how rare they will be, expected cost to own, etc. We'll just have to wait and see.
Spirit Storm is the only card I worry about. Future afterlife effects will always have to consider the existence of the card. On the other hand, there are no afterlife-based decks in the meta at all (except arguably control Anubians that Devoted runs). For now, I'm happy to see the card. If it needs to get nerfed, it's easy enough to move it to 3 mana.