Some features I'd love to see in Reason 8 (or even a 7.5 release) would have to be...
1. Ability to adjust the volume of multiple faders on the mixer
2. To be able to create curved fades when editing audio
3. Improved orchestral sounds
4. Dedicated granular effect/synth
5. Ability to change the colour/theme of Reason to be darker and easier on the eyes for long sessions.
6. More clip colour options
7. Support for retina resolutions as well as a new and improved visual makeover