I hope so, and I hope they're all Energy Weapons.

Man, when O:A was released, good times.

Umm the Fallout 2 Gauss weapons were slugs throwers which if I remember correctly were basically Rail Guns which accelerated metal slugs through a series of electromagnetic rings to hideously high speeds, which if those are the ones used in New Vegas probably put them into the Slug Thrower Guns category rather than the Energy Weapons one.
Back onto the topic at hand. Why would or even should we want to be able to import our
Max level character from Fallout 3 into New Vegas or even be able to 'import' the exp, weaponry etc from it, I think that doing so basically defeats the whole purpose of the game and also deprives us of the
fun of levelling our character up from scratch.
As others have mentioned why should we expect to be a 'Wasteland God" so to speak from the get go, doing that remove the uncertanty, thrill and satisfaction of surviving difficult situations due to the disability of being able to walk through most of the opposition in the start. Plus with the combat changes you could end up seriously mucking up your survival chances near the end game sections of the game due to having been able to blow through the opposition with no or little effort up to that point and due to that you would not have had the chance of learning how to cope with different types of foes which are resistant to different types of weaponry.
Personally I find at least half the fun of a RPG is in the levelling up, trying to decide what better fits the character concept I'm using for that character and also the uncertanty when you enter into combat of whether your character will survive or not.
Lastly as others have already mentioned while the concept of being able to import your character from the previous game in the series may work in linear series's like Mass Effect, Fallout is a disjointed series where each installment has a different main character from the others. To use a literary comparison Mass Effect is like a Trilogy in which each book follows on from the last one like the Harry Potter Set of books, while Fallout is more Terry Pratchetts Discworld series of books in which most of them are self contained stories set in the same world (before anyone brings this up, Yes I know that some of Pratchetts Discworld books can be considered to be a 'sequel' to another one or ones in the whole series, my point is that they all do not automatically flow from the previous book in the series to the next book in the series).