The Gamekyo translation apparently confirms a sequel to Uncharted: Drake's Fortune, but it's a little sketchy if we're being honest. It says:
One expected it and Christophe Balestra, vice-president of Naughty Dog, officially confirms it at the time of an interview with LCI: very good Uncharted: Drake’s Fortune will have right to its continuation, of course better according to statements’ of the creators. One awaits the first images and information.
So there we are. We'll get a comment from SCEE tomorrow.