At this time, shipping separately from the OS allows us to update more
frequently. We currently don't have plans to ship in-box, but this could
change in the future. When Honolulu GAs sometime next year, it will be
licensed as part of Windows Server even though it’s a separate download,
and it will be officially supported in a way that is consistent with
other Microsoft technologies that are licensed with the OS or with an OS
supplemental EULA (such as RSAT).