The Lucifer doesn't appear as fluid as Rebellion or Gilgamesh, but it would seem like an interesting weapon when surrounded by a great deal of enemies. http://www.youtube.com/watch?v=-gUKfz3bmaQ It's reach is fairly decent and can leave a number of the flower-like projectiles suspended. It's almost like Dante's own version of Vergil's spiral swords, except you actually have to equip the Lucifer as your dominant melee weapon. Another interesting option that seems available is the ability to select through all your weapons in mid-play as you wish with the flick of a button. Dante also seems to be able to do a certain motion (it looks like he snaps his fingers) followed by a slight glow. At first I though it was Devil trigger, but his human form persisted. I don't know what style was initially equipped for this demo, but after the first motion Dante sprung into gunslinger (if you notice he starts crossing over his guns). This is pure speculation on my part, but it could be possible that we can also switch fighting styles in mid-play as well. EDIT: Apparently we can switch styles right in the middle of game play.
Nero vs Dante There's a few more videos on the site I'm not going to bother with linking. They're easy enough to find.