That's the real time graphics MistaX, rendered in all their polygonal glory. The reason you don't see the gun is because it's a very early build of the game engine and only includes the basic game engine and a few models. (Look at the backgrounds, they are not as far along in the process as the character models)
And more that that, look at the joints... CGI hasn't had seperations at the joints for several years now, not to mention the jagged edges)
The tentative release date is 2003, but I wouldn't expect it until late 2003 or maybe even 2004. This is Id's flagship title and they are not going to be scaling back the graphics to accomdate people with slower PC's. Carmack has already stated that as fact. (And by the time it comes out it will have a much larger target audience due to another 1.5 - 2 years of PC upgrades.)