I think the consensus actually is that its probably flat, at least my memory is saying this, might be wrong, hell I'm not sure if there is a mass consensus. Before Flerfs get all wet pants on me, flat universe means that it's likely open as opposed to a closed universe which would be curved or spheroidal. The basic premise I believe is...if you set off in any direction in on open universe, you will never return to your origin point. In a closed universe, you will eventually return to where you began without changing course.