Well, what would I think would win worlds? Well, the following four decks are very strong canidates for this possibility.
Luxchomp
Sablelock
Luxpluff
Plox
My reasons are as follows:
Luxchomp: As everyone knows, Luxchomp is pretty much the BDIF in our format right now. Since Luxchomp can pull off cheap and easy KOs using cards like Luxray GL or Garchomp C, it is no wonder this deck can be very good right now. It can even run lots of techs to help it against other matchups too, like Crobat G. Moreover, the deck is pretty fast, so it can potentially out speed many other decks, and it can even cause some nice disruption with cards like Power Spray or using Luxray GL or Garchomp C to KO draw power cards like Claydol or Uxie Lv.X. Also, nowadays, many Luxchomp builds are starting to run ERL as a tech, which thanks to ERL, Luxchomp can turn even more dangerous. Thus, because of Luxchomp's speed, disruption, and great attacks that can take prizes early in the game (primarily by sniping the bench), there is a very strong chance that Luxchomp might win worlds, and it won't be surprising if that happens.
Sablelock: Ever since it won U.S. Nationals in masters this year (as well as many of them being played in Top 128 cut this year), it was no doubt that Sablelock can be one very good deck. With cards like Sableye, Honchkrow G, and Garchomp C (all of which are the decks main cards), Sablelock is indeed one mighty deck. The deck's notable strategy is too either go for the donk early in the game, or start causing disruption in many ways (primarily using cards like Judge, Giratina, or Cyrus's Initiative to disrupt the opponent's hand, and then using Chatot G to give your opponent bad top decks, or of course, stop your opponent's key Poke-powers with cards like Power Spray). Both the disruption and the donks from the deck are all thanks to Sableye, which can achieve both strategies. The deck also has good sniping ability too, thanks to Honchkrow G and Garchomp C that is. Like other SP decks, it runs other techs to help it against other matchups too. Because of how the deck "locks", donks, and snipes, there is also another good possibility that Sablelock might win worlds, but like Luxchomp, I have feeling that this can very likely happen since Sablelock is a deck that pretty much sits right behind Luxchomp.
Luxpluff: This deck has been popular ever since states, and this deck can be pretty good for many reasons. First off, this deck is very fast. Cards like Rare Candy and BTS can help you out speed many other decks easily, including setting up some Claydols to give you good set up so that you can pull out a lot of Pokemon to start KOing early. Secondly, the deck hits pretty hard too. Jumpluff's Mass Attack can hit for 10 times the number of all the Pokemon out in play; so, that means if you can give it an Expert Belt and play down some bench Pokemon, you will be sure to hit for a lot of damge (140 at the max if the Jumpluff has an Expert Belt and there are 6 Pokemon out on each side). It also has some nice disruption, where with the help of Luxray GL, Jumpluff can effectively KO some of the opponent's bench. Moreover, the deck is very easy to use, as all you need to do is pull out some bench Pokemon and a Pluff, and voila, you are ready to go. For these reasons, there is a possibility of Luxpluff winning it, but maybe not as high as Sablelock and Luxchomp have now though.
Plox- With cards like DCE, Expert Belt, and Judge, Plox is pretty good right now. In fact, this is quite evident because many of them came in Top 128 this year. Like the past, the deck's main strategy is to lock using Gardevoir, and then you use Gallade to KO high HP Pokemon. Not only the deck can lock, but it can also hit hard too. The deck can even run many techs so help it against other matchups, like Dusknoir or Azelf Lv.X. Nowadays, many Plox builds are running Spiritomb to effectively trainer lock in the beginning and start the evolution on many of your Pokemon. A Plox variant using AMU has also become popular lately. Because of AMU, the deck can further improve its locking abilities. Thus, because of Plox's great power-locking abilities and its hard hitting attacks, Plox might have the chance to win worlds this year, but it is paired with Luxpluff for that chance as like the previous deck I mentioned, Luxchomp and Sablelock have a stronger chance of winning.
Based on what I believe, I have a feeling the Luxchomp, Sablelock, Luxpluff, and Plox will all have a strong chance of taking first this year. Of course, there is the possibility of tier 2 decks winning too, like Cursegar, Gyarados, Donphan, Machamp, Gengar C, or DialgaChomp, and there is also the chance that we may have a new surprise deck winning too, like a deck made by the Japanese. Of course, if these tier 2 or surprise decks won't win, they will still at least make top 4.
