So far i've contributed to Wasteland 2, an old style post-apocalypse tactical RPG, and "Tales of the Emerald Serpent", a shared world anthology novel by several authors, including marthawells and Lynn Flewelling. Both of those have been successfully funded.
I also just contributed to The Banner Saga, a console style turn based tactics RPG with a Viking theme. That project currently has 8 hours left to go, and if they can get another $23,000 they're going to try to add player owned upgradeable cities, something i'm really hoping they manage. So if a Viking themed turn-based tactics game on PC sounds like something you might want to contribute to as well, have at it :)
I'm also considering contributing to Wollstonecraft, a series of young adult books. To quote the page: "This is the made up story about two very real girls – Ada, the world's first computer programmer, and Mary, the world's first science fiction author – caught up in a steampunk world of hot-air balloons and steam engines, jewel thieves and mechanical contraptions. For readers 8-12. This is a pro-math, pro-science, pro-history and pro-literature adventure novel for and about girls, who use their education to solve problems and catch a jewel thief."