Notes:

We have HUGE news coming your way! In 4 days time, we will be revealing something very exciting right here. Let the guessing game commence! – LEGO Facebook page

This is speculation on my part, but look at the 6 colors on the edges of the image.

Edit: Also, the same image from the LEGO Google+ page: https://lh3.googleusercontent.com/-HxDScdVnC7M/VBb_cE8hkVI/AAAAAAAAfHg/GrrJrOoFmF0/s865-no/Bionicle-4-new.jpg20140915-4177-5fuc51.jpg