I'm not sure whether Deb answered Nemo's question. I think Nemo may have meant using the style like that on the Italian Wikipedia results. Interestingly, that particular layout doesn't seem to be included on the cross-wiki design page, though it is similar to some of the tabbed designs. I think it should be included, so I'll try to add it.
What Deb was responding to was whether we'll have an on/off switch for the cross-wiki results, which we will. Whether there will be multiple interfaces available for cross-wiki results is not something I know the answer to.
Now Nemo and Deb can both tell me I misunderstood them. ;-)