If it's going to be so grounded, then the ninja aspect of the game will probably be really brutal.We've seen some of it already, like using the grappling hook to climb to the roof and then the multi-takedown in the temple and the fire bomb assassination in the PGW trailer. The leaked info also says you'll get access to various tools like Shuriken, Kunai and poison.
Basically expect a mixture of AC and Tenchu.
PSX would be a great venue to reveal that footage.