Well, it's a trademark filing, that's what.
Square Enix Europe, formerly Eidos, has trademarked Deus Ex: Human Revolution. This could either be the official name for Deus Ex 3, the upcoming prequel entry in the cyber-punk series or it could be a spin-off.
With Deus Ex 3 on the horizon and taking into account the game's teaser trailer, the "Human Revolution" subtitle makes a heap of sense.
The upcoming entry in the series will apparently feature a more lively pace than previous titles.
Have You Heard Of Deus Ex: Human Revolution? [Siliconera]