This has to be the biggest meta shake up since release, not many of the old decks seem to have survived. I suck at making new decks, so I've tried a few of the old ones and I found surprisingly that a modified freeze mage with 2x torches is pretty decent against the plethora of C'Thun decks out there. In a month or so things are going to settle and we'll have a clearer picture of what the meta will be.
Btw, the most cancerous deck I've played against was a druid hybrid C'Thun/mill one with Naturalize, Tree of Life etc. May be a gimmick deck but felt so bad losing against it.