It's about being fun, not how brilliant your orchestral score full of weeping orphans can be
Now that you mentioned it, I do think that the audio side in terms of in game music is, well I can't even put words to it, but it isn't anymore what it used to be. Back then a lot of the action tracks were really catchy and you would find yourself whistling them time by time. Maybe it is not so anymore because games are not supposed to be arcadey or something. Yeah, title tracks when the main menu opens are usually good, but I'm talking about in-game music here.
What's wrong in doing in-game music like they did in Wing Commander II, Journey to Silius, Turrican and Great Giana Sisters? Come to think of it, what's the problem in doing games like those nowadays?
Back to topic, I don't mind automatic health regeneration that much (though I like the medkits more), but it's the two weapon limit in the trailer that boggles mind. 3D Realms says that they changed the interface because they couldn't find a nice way to switch weapons with a console controller.

George Broussard mentioned that they had compensated it in level design - I don't know how well this could keep up the immersion. I do hope that Gearbox switches it back to all guns available at least for PC. I understand that this is a good choice for multiplayer where consoles would otherwise be in disadvantage, but for single player campaign in PC, I'm most likely not going to like it unless they manage to do it tremendously well.
Perhaps it is about characterization and in game rules that should be clear from the beginning. Duke is supposed to be a massive one man army so all guns available at any given time sounds reasonable by the in-game logic. However, CoD4 and FarCry 2 are supposed to be more realistic with limited carry capacity, which kicks the player back in the nadgers when he realizes that in order to frag some one, three(!) sniper shots to head are required (yes in multi). I left the game after I had lined up a perfectly good shot right to the back of the head, stabilized for a couple of seconds, shot and hit the guy only to be killed a fraction of a second later by the
exact same player emptying the clip at my present location. Well, it was highly unusual and I didn't even think the game could allow that. I haven't touched either of the games after that. So perhaps it's about consistency?