Finally got sound working in these videos, yay! New features in this video include the aforementioned shadow mapping and reloading, a brand new three player map called Orbit, and heavy modifications to the original Impact level.
I really cannot wait to get the multiplayer up and running, and get people playing the beta. Next on my to-do list are a few standard online features: basic match-making, in-game chat, etc.
Without further ado: