It has yeah, but I have no doubt he's fully capable. While the final battle in Avatar goes very much for the grandeur of war his dedicated action films didn't really tackle, he still clearly has a great sense for action pacing. Even the short action scene in Titanic was excellent, and more inline with his T2 style of intimate action for lack of a better term. If and when he gets around to giving us Battle Angel (or Prometheuses, whatever he wants), I'm sure he'll be in fine form to deliver.
It's kind of off topic, in fact fully off topic, but has there been any indication of The Abyss coming to bluray? I can't imagine the hold up, Aliens was waiting to be part of the collection, Titanic was waiting for the centennial, what's going on with The Abyss?