I think it's just too soon to judge . The upcoming release of may help it see some play, until then we can only make guesses.
I'm not sure how people opting to try other decks is the "Fall of Warrior". It's mid-expansion release and people want to try new decks. Once everything settles Warrior will most likely return to being the top played decks because it will most likely remain the top winning deck. I guess "Karazhan Freshens Meta/Ladder" wouldn't have the same ring of a title. Interesting article though.
Where I am on the ladder, I'm finding a greater variety of decks than a few weeks ago, definitely. But while all the new Hunter and Beast Druid archetypes perform well against Control / OTK / C'Thun Warrior, I'm finding Aggro Warrior to be quite successful still. Interestingly enough, my biggest struggle at the moment is against Priest nowadays.
Don't forget about the value!
While Hunter and Druid have been a little more popular since The Opera, Dragon Warrior is still very prevalent in the metagame. Sjow recently hit #1 legend with his version and I personally finished 88 on the ladder this month. Curator with Monkeys have made the class even stronger and its still a top 3 deck imo.