Well you've beaten Second Life already...
http://flickr.com/photos/bryanalexander/2187702528/It's already looking good although it has a flaw imo. That "ring gate stuff" doesn't really blend into the scene yet and looks too much like a prop placed on the floor than being part of the room. I'm also not too sure about the frequence at which those gates show up in your first screenshot (I'm talking about those four rings right next to the fountain section). I'm not entirely sure but they imo are too close plus afaik they only were that close in the part where the doorway behaves like a "donut" and as such the entire "tube" you walk in goes up like on this foto:
http://www.trashotron.com/agony/images/2005/05-columns/04-18-05/louzocalo.jpgWhen it comes to textures and shadows you don't need to bake the shadows into the textures as this is/will be possible for models (I'm not up-to-date with the current workflow for this but at some point the A7 lightmapper will work for you pretty much as you know it from blocks). So maybe put up the texture resolution a bit / add more textures or details and use shadows generated by a lightmapper. This also is going to add a lot of atmopshere to the scene...
Enjoy your meal
Toast
