So I've been following the manga quite religiously and have done some calculations. It 's a monthly manga so that means 12 chapters are published a year. From those 12 chapters the animators can adapt about 8 episodes. Since a season would at least need 24 episodes, and 24 divided kwa 8 is 3, it makes sense for the animators to have taken three years from 2009 to 2013 to adapt season one. Hence it's only expected that season 2 may take the amount of time. But that;s it. Its been 3 years. Let's count: 2013, 2014, 2015. Yup that's three years.In that time zaidi than 72 chapters have been written, subtracting that first 36 chapters used to adapt season 1, that's a whole 36 chapters left to adapt season 2. And if what I read is right, they plan on making the series span over 75 episodes. So 36 chapters is enough material for the animators to make a season 2, I mean they used the exact same amount of material for season one without the need of a pile of fillers. In fact, I'm on chapter 75 right now, which according to my calculations of evenly dividing chapters among seasons, is actually season 3 material!! So when the long awaited season two does finally arrive, most of us kwa then will be aware of the plot of season 3 let alone season 2. I don't know about you, but that kinda kills the anticipation.

Normally what would have happened had Attack on Titan not gained so much popularity, the animators would have continued the story line with their own adaptation while the manga mwandishi kept on uandishi on his same pace. That could have ended up very bad ( i.e SOUL EATER, a perfect example of animators ruining the story line) au very good (i.e the 2003 adaptation of Full metal Alchemist.) .
au they would have made three years worth of filler to wait until the manga caught up.We all know mashabiki have been through that torture before, cough, cough Naruto.

Anyway, I can't help but feel the franchise is being milked. But I also don't wan't to be a whiny fan. Maybe the delay is all worth it when the studio unleashes spectacular uhuishaji at us. (Although I've never been a shabiki of the bathed in sunlight uhuishaji style).

*80 years later I browse with my wrinkly hands on the internet, still waiting to see what's in Eren's basement*