If they actually did mo-caps then that's pretty impressive, especially if they did a broad range so every single NPC didn't use the same.. exact.. animations.
As for it not being very noticeable before.. I agree. It's actually strange, with each game they came out I would be amazed with how incredible things look compared to the previous year. It makes me wonder where gaming and animations will be in another decade.
Hahahaha yeah I can see it getting worse as the quality in NPC appearances increase. I can only picture the Halo 2's blur cutscenes with the original Halo's bipedal animations.