Battery life. That's been a weak point for 99% of smartphones. Manufacturers always skimp on battery size. I'm hoping M can help us on the software side.
I'm mostly excited about the permissions because there are some apps that I want to use, but I don't necessarily like the idea of them just being able to go through my contacts or read the files that I have on my internal/external storage.
Better battery life and native fingerprint. USB C too, so many stuff that I'm looking forward to. one of those statues would look awesome on my desk. Hope I win one!