A little bit of better news:
The Boeing Company : Fuselage panel falls from Boeing 787 Dreamliner in flight | 4-Traders
Most interesting bit:
"It was the mid-underwing-to-body fairing located on the belly of the airplane on the right side," Boeing spokesman Doug Alder said. The part "provides a more aerodynamic surface in flight."
Again, if a 8x4ft panel would be missing pre-departure at that spot...