Square Enix yesterday trademarked the name Deus Ex: Human Defiance, starting discussion that this is set to be the title of the next game in the Deus Ex series.
There's also a Deus Ex movie currently in development, which is based on the most recent game in the series, Human Revolution. The title sounds more like a sequel to me though, and we can only hope that is indeed the case. Deus Ex: Human Revolution (terrible boss fights aside) is one of the best cyberpunk games of all time and I'm itching for more of it.
E3 is just around the corner, and rumors have suggested that the Human Revolution team is working on a next-gen title, so maybe we'll see a new next-gen Deus Ex game unveiled in June? Fingers crossed.