Surprising no one, AllThingsD says their sources tell them Apple's next invitation-only event will be held on Tuesday, October 22.
They go on to say, "The focal point of the gathering will be the latest updates to the company’s iPad line, but the new Mac Pro and OS X Mavericks will likely get some stage time as well, I’m told."
I'm told we'll get release dates and pricing for the Mac Pro and Mavericks. Little hint - Mavericks will be available immediately. http://allthingsd.com/20131008/apple-will-hold-fall-ipad-event-on-october-22/