I think that what Tomb Raider did is a good first step. I would be very interested in a game that only had a handful of kills in it. Kills that had meaning and an emotional impact on the game.
What if instead of sending 20 guys at you with rifles they had more elaborate tombs? I found the tombs to be a joke compared to what Assassins Creed has been making in their tombs.
The real question is "Does Tomb Raider NEED to have that combat mechanic?". When you were done with Tomb Raider what did you think about the next day? The assault rifle or the story and setting? What if you just had a bow for hunting wildlife? I really think there is possibility for some amazing innovation if developers will stray from what has always worked.