This took 3.5 hrs to render (2.8ghz, 1gb) and used:
-Depth of Field
The displacment mapping and depth of field added considerably to the render time. But amazingly the blurred reflections rendered without much extra. Also the HDRI was much easier to setup using the IBL node and final gathering preview was awesome for adjusting the intensity of the lighting rather quickly.
Any ideas or comments would be appreciated. I'd like to hear about your experiences with the new version of MR. :)