I am looking forward to seeing what the teams in the Collaboration Studio can achieve armed with the Unreal 3 engine, 3ds Max, CS3 and more.
The article by Matt Vela at Business Week showcases how the giant US Architectural firm, HKS, is using the Unreal 3 engine in its practice. They have embraced the technology enough to not only use it in all their large projects, but now to license the software including the source. I found it interesting that adoption of technology like this dint just allow new perspectives of the schemes and afford clients a better feel for them - it also generated more dollars for HKS per project.
(Though not using Unreal3 - the animations on the Heartwood Studios site is neat as well)
Unreal 2004 Arch Vis
This Youtube vid shows off an Architectural model, apparently done by a 5th year Architecture student (perhaps even of their design work).