The next release of Minecraft—the so-called "Adventure" update, AKA Minecraft 1.8—is now, somewhat unexpectedly, in the wild. And its creator is perfectly fine if you go ahead and grab the leaked release.
"Ooh, looks like 1.8 has leaked, not that I'd ever admit that," writes Marcus "Notch" Persson on his Twitter account, winking coyly and offering the following reminder. "Be careful when installing software you don't trust though."
"Make sure you get it from the leaked url we are hosting," he adds. That would be this JAR file.
So, go on. Get your low polygon adventure on, but heed Persson's other decree: "If you do use it, remember to report bugs, and to feel slightly bad."