Released: Exchange Server 2013 RTM Cumulative Update 1

@manf0001 - the reason why there is no in-place upgrade is that it is super-complex. In last several versions of Exchange, we have been making significant changes to database engine for example (amongst other things), rewriting significant parts of Exchange into managed code etc. It would be a very large work to enable in-place upgrades. Having been there though in the past, we have learned that despite our best efforts, if in-place upgrades go wrong, the recovery is much more painful than having to move the mailbox back, as the server can be in a semi-installed state. Lessons we learned in support showed us that it is not necessarily something that does anyone any favors...