Didn't watch most of DWC but the games I did happen to see were the same match up 3 times. Nothing that I saw really stood out, except for the Songhai decks but that is more due to the fact I want to learn Songhai more but I just don't have the cards like Fox, Zendo etc to make a good deck.
Its probably why it did so well at DWC because people didn't expect it. I'll be teching in Crossbones for a couple of weeks since Mech will probably rise in popularity. On ladder its a thing that is always around, but goes up and down in popularity a lot more than any other deck.