The answer is, apparently, at least a partial yes.
According to
attackfothefanboy.com, the Swedish developers responsible for the Battlefield series will indeed assist BioWare in the development of
Mass Effect 3's weaponry.
They'll specifically aid in the development of bullet physics, weapon sounds, and environmental damage - all things I'm under the impression the Battlefield series excels at.
So is this good news or bad new? I say good.
In a game that, at least partially, has always thought of itself as a shooter, the guns have always been a bit behind the curve. The best shooters have guns that are characters in their own right, but guns in ME1 had zero character. They were empty vessels to cram full of upgrades. Mass Effect 2 remedied many of the "characterless-gun" issues that ME1 had but still left a little to be desired in my opinion.
So I say if BioWare is willing to push it even further in
Mass Effect 3, then I'm all for it; and if they need a 3rd party to give them advice and aid, then DICE is a solid choice. At the very least, it suggests that BioWare will not have to sacrifice so much of their collective creativity on getting the guns just right and can, instead, spend that creativity on what they do best - the RPG aspects and story.
I love shooters, and I love BioWare RPGs, so a BioWare RPG with a weapon-design philosophy culled from the arena of modern realistic military shooters is a bit of a dream scenario for me.