Not sure if the amount of effort to include metadata and data mining functions would be efficient use of Sonar Development. If you already own SoundMiner (any version) you have a robust librarian solution at your finger tips that has functions which can easily let you scrub sounds, preview, manipulate and then "inject" a sound or batch of sounds into an open DAW. I know it was pretty well integrated with Pro Tools back when I was using it for feature films, but I can't speak to how easily it can "send to Sonar" if it does at all.
I can see starting small. Being able to embed and manage meta-data for clips in a project - especially since they've made it super easy to drag from the timeline into the browser and quickly save out things like midi files, wave files (acidized or not).
Most sound designers I know have no problem using other daws that lack sound-mining functionality but I can imagine if any DAW were eager to start integrating features sound designers would want, I for one would be concerned with making sure that file exporting (getting stuff out of a working session and into a "vault") is accessible and intuitive.