The Blog Composer now autosaves once per minute while initially composing. After autosaving, the preview generates, as well. If you leave the Blog Composer without actually saving the new blog, it remains in a draft state with just the Title, Body, and Category.
Since this is a new feature, I expect there will be bugs to work out. However, during my tests, it seems to be working without any major issues.
Also, several of the keep-alives have been resolved in various areas across the Community. This should resolve issues for which sessions would time-out when doing something like painting a picture for 2 hours.