I don't think it will feel like a been there done that feeling. There are some cool new things they are adding with multiple paths through the level which will break down the heavily scripted feeling. Also, I love the addition of vehicles and the physics driving them. The vehicles in the other games felt silly. The physics in the game is way ahead of anything I have seen which makes the world feel more alive. Also, I like how the traversal is not separated out from the combat. It shouldn't feel automatic. There needs to be some challenge. The same goes for the set pieces and puzzles.
Everyone knows the one area that sucked in previous Uncharted games was the AI and combat. It's dated and not brilliant. This is especially true in part 3. It felt too videogamey. The AI didn't feel natural with the snipers, grenades, and RPGs always pointed at your head no matter what like you are a bullet magnet. With their terminator-like vision, they see you even when you are behind walls. The terminator like enemies that didn't even flinch when you shot them didn't make the combat better.
Just by improving the AI and reactions of the enemies, this game will be infinitely better than the previous games. When you shoot a guy in the leg, he better fall over not behave videogamey and start running around like he's on some crazy-sh*t. It would be awesome if the combat was finally better than Gears Of War. Before it was just something you got through to see the spectacle. This is my only worry about the game.
Even if it still has all these problems, the characters, adventure, and most importantly cutscenes/story will propel this over 90. It's so much better than anything out there.
