Microsoft's Cortana is currently limited to only those in the United States, but the team behind the personal assistant are working hard to quickly bring it to other regions. Top on that list is the UK and China, two regions that are officially getting Cortana soon. Cortana was originally teased as coming in July, but Microsoft later backtracked on that as the date was pushed back.
Now, Marcus Ash, Group Program Manager of Cortana, has responded to a user's question about the UK, noting "Barring an unforeseen issue, down to less than 2 weeks for the developer preview." This is certainly good news, as many in the UK can finally take advantage of a proper regionalized Cortana, including metric and Celsius data. As to the reason for the delay, Ash explains that he and his team have "…learned a lot about scaling. Now we need to finish" observing that it has been a "tough project".