I seem to have the update (Cambridge). Flicking around the menus seems to be a bit crisper, although it may be a figment of my imagination, and it's not as snappy as my old Sky+ HD box. If I go to "Help & Settings" > "System Info" there's an option there for "Multi Room Streaming"...
As you can see, it suggests you go to the Help section for more information, but I can't find anything there, so maybe that's not written yet. I'd like to give it a go if anyone has any suggestions. Maybe I should just network the boxes and see what happens?
Anyone want me to try out anything specific, or want to see particular screen shots? Happy to oblige if so.