There is discussion that the vertical stabilizer had been damaged either during manufacture or shortly thereafter, something about coming de-laminated, repaired by the contractor, then attached to the plane. Also, this aircraft had suffered a severe turbulnece incident about 7 years ago - severe enough that 42 passengers were injured. I had heard this information on the news this morning. Now, if the vert. stab. already had a problem and then suffered some severe forces later on, is it outside the realm of possibility that it could shear off later on? On the thread above, there are photographs of the stabilizer - it looks like it broke off pretty cleanly. I ain't no expert here, but is it possible that this really was an accident? Also, there is another thread on this forum about the airbuses now being inspected.
I expect now i'll be flamed as a gubbmnt sympathizer.