I've noticed that Nords in Skyrim typically pronounce their "j" as a "y," and I was curious if this pronunciation was just how the voice actors normally spoke or if there is some kind of under-lying lore. I seem to remember Mark Lampert mentioning he wanted "to see if we could try out the 'Nordic accent'" in one of the teaser videos that came out before Skyrim was released. Is this "accent" referring to the Nord race of Skyrim and their speech... or just generally referring to the speech of Norwegians, who are technically "nords." Seeing as there are multiple lore articles on the languages of Tamriel, I thought that there could be some kind of official pronunciation of Nordic Cyrodiilic. Any thoughts?

The latter. Nords in Morrowind sounded more Scottish or Irish, and more-or-less American in Oblivion.

Don't Nords have the same voice actors in both games?

Potentially. When I say 'sounded Scottish or Irish', the specific line that comes into my head is the 'Standing pretty close to the fire' one, which has some non-American inflections. Nord Women sound American in both cases.

Yup, they are indeed the same VA. Johnathan was clearly given directions to sound more like a lovable oaf then a rugged man of the north in Oblivion.

True. Guess you can't go too in depth with voices... Just pick the actor with the coolest sounding voice.
My own explanation for those earlier voices: Immigrating Nords picked up local accents.

Hmmm, Nords with a bit of Ashlander cancer-throat?