Roberto did a keynote at the Lua workshop '12, where he detailled what keeps the Lua team busy. A video of it exists somewhere on the web. Half of it was about

Roberto did a keynote at the Lua workshop '12, where he detailled what keeps the Lua team busy. A video of it exists somewhere on the web. Half of it was about how to integrate IEEE doubles and 64 bits ints soundly in the language. There are some challenges left, but they're really trying to overcome them.