Yeah, there has always (?) been a stack of two portals. What's new is that this one has two Linden Realms portals side by side, one marked "Premium." Premium accounts haven't been around so long, and AFAIK no mention has been made before of premium members having a different experience in Linden Realms. A premium account is way out of my league, but I'm curious what the benefits in Linden Realms might turn out to be.