> Can you please explain how this is different from how it's done today, and 
   > what the benefits of the new or drawbacks of the old version are?
   
   - better concurrency.  (ie. make -j)
   - consistency with the rest of tree.


it also makes UPDATE builds faster i believe, since it only has to
rebuild the .d files for the changed files, not everything (except
the libs -- libkern & libcompat already use separate .d files.)


this would be great.