Energy weapons are getting -DT to all ammo types excluding flamer fuel in the next patch.
And Explosives are also going to get tweaked a bit, how has not been explained.
This is true, though if Obsidian had made them a worthy alternative to guns, like they should have been, I'm not saying that they should be equal to guns in every way, they should have both advantages and disadvantages compared to guns, and New Vegas already has the disadvantages covered, they're less common, and ammunition for them is harder to find, which makes sense, too bad New Vegas forgot to give them the advantages. But at least they're trying to fix their mistake in this regard, of that, I'm glad, at least it shows that they realize that they didn't make energy weapons like they should have been. Too bad that until the patch is released, we can only rely on mods to fix the problem.
So yes, I would say that energy weapons in the game are rather underpowered, and so are explosives by default. Energy weapons, as I see it, should be quite powerful, especially against heavily armored targets, but as it stands, they're actually a rather bad choice to use against armored targets. The loading text claims that plasma weapons are supposed to be slow but high damage weapons, and yet when I tried to use the unique plasma rifle against a deathclaw, I still couldn't get through its armor, unless I got a sneak attack. And whereas guns have armor piercing rounds if you encounter enemies with high damage resistence, the only alternate ammunition available for energy weapons are overcharge and max charge rounds, and apparently, the damage bonuses added by ammunition don't allow the weapon to pierce armor better, making these things not very good against armor. I'd say that's a reasonable choice since it ensures that hollow point and armor piercing rounds work as intended, I guess the developers just hadn't taken into account that this design choice means that if your energy weapon isn't strong enough to pierce a target's armor, there's nothing you can do except switch to a stronger weapon, which isn't very helpful if you're already using the strongest weapon you have. As to explosives, they're supposed to be very deadly, but also not very precise, and with the risk of hurting yourself or your companions, in first person shooters, grenades are usually the kind of weapon that you can avoid if you're careful, but can kill you in one hit if you're not. Of course, New Vegas is not an FPS, and as an RPG, how many grenades it takes to kill you should depend on your stats, but I DO expect standing near an exploding grenade to be very harmful, both to the player, and to enemies, and yet while explosives seem to be effective at crippling limbs, I can see targets survive explosions with barely a dent in their health, and this is not how is should be.