I have issues since 10 minutes back of hitting the Preview button. If I do I can't save nor publish. I have to reload the page.
I also open some pages and the code is not available in the code editor, says "We cant load the code".
I also see that a lot of people have Sandbox Data Collection issues.
Is there any deployment that is going on and we should know about so we can go grab a snickers while you ride out the storm :)