Since 1520 and 1020 were both niche devices I'd like them combined into one.
For fall 2015 flagship I'd like:
6" IPS LCD @2k with glance, gorilla glass 3 or latest, less gap between screen so it should seem to pop. thin bezels, capacitive keys.
41MP 1/1.3" Rear sensor with zeiss, pure view, supersampling, haac mics, dual led + xeon and ability to use them simultaneously like a 3 point lighting system.
13MP 1/2.3" front sensor with dual led and xeon flash, zeiss and pureview.
720p @240fps, 1080p @120fps, 4k @60fps for both front and rear cameras video recording with surround sound and directional haac mic recording.
Dedicated camera button.
Stylus/Digital pen integration and inclusion in the body.
SD 810, Adreno 440.
4GB RAM
128/256Gb storage
Micro SD Card slot
4000+mah removable battery and removable back cover.
Finger print scanner.
Dual Stereo Front Speakers with Dolby audio.
USB OTG
SD card slot.
Micro sim slot.
Thin metallic sides with curved removable metallic back in gold, silver, white, grey, black, crimson, navy blue, lime, orange, yellow, pink, cyan, mauve, steel, chocolate colours, Qi wireless charging, turbo charging.
I don't care if they price it at $1000. I'd buy such a device in a heart beat.