DS saw everything from a young age. Star Wars, HP, LOTR (not ROTK, we previewed it and the Smeagol bits were too intense), Spider-Man (Tobey Maguire edition), POTC... I'm talking little, four years old.
He's a quiet kid but nerdy. He loves fantasy and sci-fi, so that sort of action/intensity never made him shrink away. It'll be interesting to see how it goes with DD.
Lara