One thing I'm happy about is they are getting rid of WiFi sense, the little loved feature that automatically shared your WiFi network password. You could decide who it shared your password with in the settings, but I'd rather pick and choose who has access to my network individually.
There are quite a few, the largest are probably Windows Hello, Cortana and Ink.
Windows Hello will allow the use of biometrics to sign into account both in app and through the Edge browse. Edge will now allow browser extensions and other improvements.
Cortana will be available from lock screen. It will also push notifications from you phone with both Windows and Android phone support. Cortana will also be able to make appointments, interact with apps and potentially become an actual assistant.
Windows Ink will allow native app interaction with a pen allowing both drawing and note taking. You will be able to easily interact with Maps, Office apps, and sticky notes, and MS encourages app developers to add the support for Ink.