Apple’s October 16th product announcement begins at 10am PST; 1pm EST. My guesses? Definitely: OS X Yosemite, iTunes 12, and the next-gen iPad Air and iPad mini.
Maybe: Updated Thunderbolt 2 + Retina display (I’d guessed at this last year and was wrong), iMac with Retina display, updates to the MacBook Pro line, Apple TV 4 with support for third-party apps.
Not a chance: An HDTV, more info about Apple Watch, a mega-sized iPad, or a pull-string-to-talk Steve Jobs doll.