I too had recalled hearing that David would have his head and shoulder area separated from his body (presumed by battling an Engineer).
Hoping that this isn't the end---but it seems to be about a close as you can get to a climatic ending as I can imagine after the Juggernaut crashes in a million pieces planet side. We have also heard that Shaw and Vickers would be the sole survivors.
The turn of events are still a bit shaky in my head--so I can wait until "Prometheus" opens to disseminate it further myself.