More Valve trolling, or fan trolling?
A mysterious website by the name of black-aperture.com a combination of two companies in Valve's games, Half-Life and Portal. It has been speculated before the two games may combine, and a Half-Life 3 is long overdue. In the two games Black Mesa and Aperture Science are competitors, and so combining the names we get Black Aperture.
The website is all black with a blurry piece of text in the center reading, ".../3" Valve have continously teased the fans with the number 3 and with E3 on-board, it could be the moment they have been waiting for.