unless changes are coded to the present source or the upcoming 9.2 work (that I still have not had a chance to review due to a few other things going on ) I believe in btc 9.2 lets you set whatever you want as a fee (Which of course advanced users can do now) however sending a tx with no fee means you may not get confirmed quickly  ??  I know with btc from reading posts and listening to lectures Gavin says miners should determine the fees.
I am not making any suggestion as to what fee's should be 'coded' to or forced to or even saying that needs to be done at all.
Just pointing out that a few tweaks to the advanced features of 9.2 may be necessary to make these changes if whoever makes the final choice wants a minimum fee set.  These changes may not just be commenting out a few lines of code either.....