I haven't tried the multiplayer as much, but it seems much better than the single-player. The replay feature is very cool, and I hope that becomes standard on console games. All Bungie games have had replays like that since Marathon, but usually they are not as well integrated as they are in Halo 3. It is also nice to be able to take screenshots and upload them, like I did to demonstrate how they are handling
water splashes.
I think Halo 3 has the best multiplayer I have seen for 360, but I am still having the most fun with the Quake Wars demo
![Smile :)](./images/smilies/icon_smile.gif)
I think the Halo 3 multiplayer is improved by the sheer number of players who are playing on it, so it is easier for their 'matchmaking' service to find other players of similar skill level and connection speed.
I also have to say that that video you linked to is just dripping with hyperbole; it is not actually that hard at all to implement replays, and it is in no way a new idea.