Low light and the heavily compressed H.264 codecs are the GH4's main problems. The codecs limit the GH4 and adding RAW or at least ProRes to the H.264 codecs gives more options.
1. Better low light hopefully with the long awaited High Dynamic Range low noise Organic CMOS sensor.
2. Internal Recording with up to 4k 10bit 422 HQ 25fps ProRes plus 4k 10bit 422 60fps and up to 240fps 10bit 422 1080p in the new HEVC/H.265 codecs.
3. External Recording with up to 4k Lossless CinemaDNG Raw or 4k 12bit 444 24fps ProRes with SDI output or equivalent.
4. Dual Image Stabilization.
5. Better Flip screen resolution.
This would be a field leveling Monster, of which I would gladly buy.