[UPDATE: Shacker Zek has correctly pointed out that Notch actually first discussed the game publicly via his personal blog a few days ago. Originally designed as an RTS of sorts, it's been simplified into a scouting and base building affair, with Santa trying to spread cheer to the world, while Cthulhu tries to corrupt it.]
Markus "Notch "Persson, developer behind the highly successful Minecraft, and founder of Mojang Specifications, has revealed some sort of new project via Twitter today. Providing a link to a browser-based engine test for something called Santa vs. Cthulhu, Persson asked folks to weigh in as to whether or not it worked, and what sort of frame-rate they were getting.
Little else is known about Santa vs. Cthulhu at this point (and there are no hints in Persson's tweet), other than what the engine test reveals.
Upon hitting the page (which requires Java to run), one is presented with a three-dimensional map of Earth that can be rotated using the mouse. A number of real-world cities dot the globe, and hovering over them reveals their names, as well as three stats: Cheer, Corruption, and Population.
We've reached out to Persson for further comment about Santa vs. Cthulhu, but in the meantime, you can check out the interesting little engine test for yourself, here.
Unless the game focuses on some sort of nog-chugging competition, my money is on Cthulhu.