End of this month, Innistrad will come out. It's the first set of the new block and has a very cool theme to it in my opinion. They are going with what seems to be a classic horror theme. It has a very gothic feel to it. Most of the spoilers so far center around humans, werewolves, campires, zombies and spirits. One of the new mechanics they have is "transfrom". They are using two sided cards(which raises some issues) that have a human on one side with such and such abilites. On the other side, after you have met the "transform" requirement, is a werewolf with various abilities.
I love the standard elves, dwarves, giants, dragons and whatnot themes but I've always been a fan of the classic monster world. Always loved the old Dracula, Frankenstien, Wolfman movies.
Spoilers so far.
http://mtgsalvation.com/innistrad-spoiler.html