Ear pieces appear more than once in the new concept video, published earlier this month. And are also plenty of big-screen devices that go beyond the recently unveiled Surface Hub conferencing system which allows for multiuser, multitouch, multipen collaboration scenarios, with lots of room for next-gen analytics and presentations.
A digital bracelet also has a starring role in the new video. (As @h0x0d discovered recently, there's something codenamed "Project Blush" in Microsoft Research that is focused around "digital jewellery," so maybe that's where this Internet of Things device has its roots.)
Gates described the coming Personal Agent technology as something "which will remember everything and help you go back and find things and help you pick what things to pay attention to. The idea that you have to find applications and pick them and they each are trying to tell you what is new is just not the efficient model - the agent will help solve this. It will work across all your devices."