I'm calling it now. 25% chance of a "One More Thing", most likely an updated Apple TV. But 75% chance of no new hardware.
Definitely no surprise announcement of new Macs, iPhones, or iPads (they're done for the year - anything new would undercut existing devices already on the way to stores and customers), there's a remote chance it might be Apple Tags, but I'm pretty doubtful they'd drop that after the holiday season has started - if it missed Fall, it might as well wait until Spring (sigh).
They're in the game business now (Arcade). An event that showcases best new apps in general, and, oh, by the way, 20% of the best apps are on Apple Arcade, could be quite beneficial for Apple.