1. The References
Innistrad is a beloved plane with beloved cards and Eldritch Moon might be the last set on Innistrad as we know it. Consequently, it's got a lot of callbacks to earlier cards in the set. From the reprint "Prey Upon" with new art altered slightly by the Eldrazi to Tree of Redemption's final fate as Tree of Perdition you physically see how Innistrad has become not just besieged as it was in Dark Ascension, but utterly corrupted.
2. Eldrazi That Haste Themselves
I love giving Eldrazi haste. I have an Elder Dragon Highlander deck based around getting Eldrazi out with haste. It has worked 0 times, but I love it. One of my favorite things about Eldritch Moon is its self-hasting Eldrazi.
3. The Lamb is a Weapon
Lambs are apparently weapons that give a +3/+0 once you're desperate enough. Can't wait 'til we get back to Innistrad and we can make and then weaponize 0/1 white Goat creature tokens.
I never thought I'd see Murder darken the doorway of a standard set again. Yet here we are. It's too bad that when it comes to crime scenes, Innistrad has no one left to...investigate (investigate was a mechanic in the previous set that's not in Eldritch Moon).
5. The Body and Soul Theme
My understanding is that Magic dev teams will list concepts appropriate to a theme--for example, Creepy Doll--then make a card out of it. Those concepts have to jockey against color balance, draftable cards, and mechanical themes to find a place in a set so its weird that this concept has two iterations. I like them both; it's just that I only expected one of them.
6. The Most Evil Card I Have Ever Seen
Wow, it's just such a terrible thing to do for yourself for four mana. It's a card whose value depends solely on player choices though, so I like and respect it.
I have a deck that was originally a Battle of the Wits deck that eschewed tutors. Now it wins by making everyone mill out by drawings cards, then discarding cards. It has worked exactly one time. Eldritch Moon has more cards for me to add to it and I love all of them as children. No, more than children.
8. The New Stuff
All of these deserve some background. Falkenreath Ravager is a 2/2 common for a 2 mana (one generic and one read), which Red has never gotten before. Usually Red could pull up a 2/1 for that price or a 2/2 for two red mana (RR). Occasionally there'd be a rare. It's a new direction, just like Stensia Innkeeper.
Red has long been able to destroy lands, but destroying lands sucks. It's no fun to play against someone when you can't cast spells. Now Red can lock down a land for a turn as a bonus on another spell. I hope it works out. It's interesting.
9. More Niblises
I've always liked the niblises. They're spirits that tap guys and Eldritch Moon adds more. I don't know if we're going to see more, but I'll be happy 'til we get back to Innistrad.
10. LOL, Wolf Head on Robot Body!