No crosshair : It's in the 'beta' (or stolen executable like John said ). If you look through the videos carefully, you'll see that sometimes it's there, sometimes it's not. Either some weapons don't have it or they have put \cg_drawCrosshair "0" while playing the demo to make it look better for the tv program.

Regarding the prospect of having to upgrade, well, it shouldn't be that bad if you have a read through my previous posts. But Doom 3 will be the first milestone to a new generation of games and I believe that the new gaming experience will totally justify the investment if upgrade is necessary.

Multiplayer: Doom 3 is focused on being a scary single-person shooter. They haven't focused their time on the multiplayer at all (or very little). But the great stuff with idsoftwares' games is that they are fully "open" to modifications. They will ship all the tools they have used to create the entire Doom 3 world with the game and the community will take care of the multiplayer aspect, as usual. After all, what's the Quake 3 multiplayer experience without OSP?