Looking to see how to migrate from SBS 2003 to Essentials? The draft docs (beta) are already posted – http://technet.microsoft.com/en-us/library/jj200183 well obviously some of them, not all.
Take the time right now to review the docs and ask questions.
The RC just posted yesterday:
Keep in mind there’s no supported path to go from the RC to the RTM so these are still play bits only. RTM is expected (as per the blog) sometime later this year.