Modern OS things that we need:
-multicore support
-smart SW shutdown
-more memory protection (if full is out fo reach)
-to be able to use more than 2GB RAM
-thorough 3D support
-better interfaces towards modern tech (bluetooth, etc)
Less critical:
-multiuser support
-OpenCL
There are some things that our niche OSs do better than mainstream Modern OSs, and we should not give away those features (example: responsiveness, light weight).