New locations, new characters, new stories, same ol' Mass Effect. BioWare Montreal is indeed working on Mass Effect 4, much like DICE is working on Star Wars: Battlefront. To that end they played this trailer at the EA Press Conference today...
Doesn't tell you much of anything, but it does look cool. Plus side is that BW Montreal view ME4 as a clean slate where they don't need to worry about the first three games at all and are just setting this in the same universe. Sounds cool, I'll game, give me more BioWare...