Actually, it looks like the game is designed around the idea that we may be using guns and energy weapons more interchangeably. I mean, a master marksman with a 10mm Pistol wouldn't suddenly become inept when he picks up a Laser Pistol. And it doesn't really ruin the role-play for a mad scientist to have to use a hunting rifle instead of a Plasma Rifle for a little while, you know?
At any rate, I'm hoping the general balance between regular guns and energy weapons stays close to what it was in Fallout 3. Where the progression from weak guns to better guns is relatively smooth for ordinary guns, but for energy weapons you're stuck scrounging for ammo and using a piddly Laser Pistol up until later in the game when you get some of the most powerful weapons out there. It's kinda like the "Warriors are linear, mages are quadratic" trope Falloutified.