I used a 3d-world collaborative environment in a remote company once, and the only effect I noticed was that it brought the awkward parts of the physical world into the digital world. Where do I position myself? Where do I "sit"? Should I "sit"? Is this the right room? What's the "physical" location I'm supposed to be in?
It was like those flash/java-applet 3D navigation interfaces for websites that were semi-popular for a few years, way back: cute, but just made everything slower and harder.