Alrighty, so I have a theory.
Taking the google earth photos in chronological order...
Mid 2008: Site begins meaningful construction. Note the more "deeply" or "reinforced" section which is dug up in the ground, circled red.
Early 2009: site begins to come together, the "deeper" section is still visible, possibly reflecting more extensive work, while the rest of the long line is already covered.
Late 2009: "section" is covered, by roofing separate from the right.
2010: A part on the diamond shaped head seems to be under work, also circled red. Little change on the rest of the facility.
Late 2011: Original "section" (circled 1) remains, the left "head" section (circled 2) has seemingly stopped whatever they were doing, while on the south eastern side, a new, exposed dig out seems to take shape (circled 3), suspiciously similar to the original construction work of 1.
Note: the buildings, which were previously on "top" of the long blue building seems to have moved to the "bottom" -- as if to be closer to section 3?
Early 2012: Construction work on 3 seems to have finished. Large, wide roof now covers it, with an extended concrete walkway or something of that sort.
So I wonder if we can take Mr Ma's revelation about the 2008 and 2010 prototypes... and link them to circled sections 1 and 3 respectively?