Why are you posting here with this I hear you cry? Okay it's got nothing to do with HL2 except for one of the new weapons that bears a striking similarity to the gravity gun. I've seen people speaking about this before (I don't think it was here. I think it was on the Steam forums) but I wasn't sure if it was just a rumour. Seems like it's the real deal though;
http://www.gamespot.com/pc/action/doom3resurrectionofevil/preview_6115832.html
http://gamesdomain.yahoo.com/pc/doom_3_resurrection_of_evil/preview/58715
http://www.gamespot.com/pc/action/doom3resurrectionofevil/preview_6115832.html
And according to a preview on Yahoo games it was an idea id were toying with long before HL2's gravity gun was revealed. Erm. Not sure what to make of that. In any case it will be interesting to see how much this new weapon shows of Doom3's physics engine & see how it shapes up against Source.The expansion will also introduce at least three new weapons, the first of which is the oft-requested double-barrel shotgun that played a prominent part in the first Doom games. The other is being termed the Ionized Levitation Weapon, otherwise known as the "grabber gun," which has more than a passing resemblance to Half-Life 2's gravity gun. The grabber gun will take advantage of Doom 3's physics engine by allowing you to pick up and manipulate objects. It will also have combat applications where you can capture incoming fireballs and rocket warheads and redirect them away from you.
http://gamesdomain.yahoo.com/pc/doom_3_resurrection_of_evil/preview/58715
Finally, and in keeping with the game's new combat engineer star, there's a physics-based weapon called the Ionized Plasma Levitator, or Grabber. "Physics plug-ins are just fun," Stratton said, and the Grabber will let players throw around smaller creatures and slam them into walls, fling barrels at enemies, and even pluck projectiles like fireballs or rockets out of the air.
Sounds a lot like Half-Life 2? As coincidence would have it, the Grabber was an idea the developers had been considering ever since they started Doom 3's level design. "The way we populated levels with objects was to drop them in, then start throwing them about with the cross-hair," Hooper told us. "It seemed like fun, so we attached a weapon to it.