I know right? It's taking forever.
But when you think about it, Scarlet City Studios released a lot of extra stuff this time. That birthday mission, the egg one, and of course Evergreen Meadows. That must have taken a lot of time and effort on their part, so they needed a possible breather. Even if they didn't, I'm sure Episode 4 is really big, it's also the beginning of Season 2 so it's even more pressure on the to make it awesome. I think we could all show them appreciation, or even a favor, by just waiting patiently and telling others to do so as well. I'm just as excited as you are, and I really hope it's released before the end of this year.
There's also some topics where people discuss things about Episode 4, or talk about what might be in even future episodes. You can find them using the forums search engine. I think, I don't really go to them that much... Anyways, enjoy your time now, because you never really know what's going to happen---
Episode 4. Comes. Out.