I believe it will be. Seeing as most, if not everyone, has a character
in the single player games that they are recreating and bringing to the table.
I know I, for one, have my Dunmer Assassin that has incarnated into every
single "save all of Tamriel instance." dating back into the end of the 3rd Era.
He has always had the same name and I felt the most immersed in the game
when I played with this char.
So everyone will have their loved character and since everyone is,
in a way, used to being the only factor in saving Tamriel in sp games and
the only real person to talk to, I think it will affect the behavior of people
towards a more roleplay gametype.
I have even rolled a Breton in Skyrim to get ready for the Breton
class I am going to have to create in order to see High Rock without it
being rendered in Minecraft graphics. My Dunmer was sure hoping to get
out of the east and see the castles of the west he heard of when he was
just a little fetcher.