Prophet said:
They were probably just testing out the Realms, before they added colors. Its hard to explain, but people who are in coding and graphics would know what I'm talking about. Lets use Halo for example, when you go to edit the elites armor, you'll notice its a white armor, not blue, thats because the script assigns the colors, coordinating with the rank.. its hard to describe.
I know exactly what you are talking about. However, everything else was perfect, well how it is now. And the portal is detailed. It has little, soul like faces floating around inside of it. It might have been an idea for a realm that got trashed, but
"I don't understand why they would leave that in the opening preview of the game"... Or like you said, maybe they didn't know what colors they wanted to make the portals yet.
EDIT: To 7th: I don't really know. I think there was a portal to the left and right of it, however, I could be mistaken.