What Cursed said :)
I'd love to get on to Act Three - I have so many plans for it! But unfortunately I underestimated both the amount and demand for side content in Act Two and so I have to get through all of that before I can move on to Act Three (which, yes, is where shit will go down, rendering the vast majority of Act Two content unavailable)
I am doing my best to get through it all as quickly as possible, though, even to the point of pushing some planned Act Two content into Act Three. I'm actually beginning to see some light at the end of the tunnel!