Wow. A few years ago they let slip they planned on 10 acts, and I laughed. We're at 4 right now, with 5 coming with this next expansion. 5 is entirely new content. And then...This. They're getting rid of difficulty modes completely. Instead, you travel back to Act 1 (Now Act 6) which has changed completely from your time there. New groups have taken over, zones have changed, the way you get around has changed. Instead of repeating the same content 3 times to get to end game, you don't repeat anything, at all.
June/July cannot come fast enough. Path of Exile is such an incredible game.