I tried that specific search and it didn't work for me. My guess is that it's being rolled out in the US only.
Now, not only will give you the answer directly in the search results, but we will also continue the conversation. For instance, you can ask “who is the president of the united states”, we will show you the answer. From there you might ask, “who is his wife” or “how tall is he.” Bing maintains the context and keeps the conversation moving forward.Bing Adds Conversational Search Responses To SERPs [blogs.bing.com]
These improvements build on extensive work we have done to build out the Bing platform including investments in entity and conversational understanding. This is a long journey, and we expect to deliver a number of additional improvements in the days ahead.