Here's the web announcement:
We covered the impending 950 and 950 XL here, of course, though some finer details will emerge on the day, I'm sure, so watch this space.
What of other devices? If Microsoft covers these two flagships properly, there shouldn't be a need for anything else, at least on the phone side of things, but there's an outside chance of a business-specific offering too, plus - no doubt - a clutch of accessories for input, for Continuum docking, maybe the 'Band 2', and so on.
Also expected at the event from the wider IT world is the Surface Pro 4, virtually a copy of the Apple iPad Pro, extending Microsoft's lead in this area. (strikethrough humour intended, the Apple device being the copy... oh well, you get the joke....!)
We're assuming the livestream on the day will be on the same URL: https://www.microsoft.com/october2015event/en-us