I am on PTO from now until July 20th .. when I get back I will publish the key dates blog and the sandbox preview instructions but for anyone who's back from holidays wondering what the dates are, here's a quick overview #Forward Looking Statement.:

• sandbox preview starts August 26
• sandbox cut-off will be August 25 at 6pm PT 
• Preview release notes are due on August 17th
• Pre-release org sign up will be available on August 11th.  If you already have a GS0 org, you'll start seeing it on August 4th.