Have the icon.size default to computed font size.

This is a proposal to have the icon size default to computed font size. Very often, icons are presented next to text of matching size. This would make it possible to set the font size with CSS and have the icon automatically resize. Does this sound useful?
Uhm, no... Im gonna do a quick test and let you know. But does the idea make sense? 24px is a nice default size but I just often find myself sizing icons to correspond to sibling font size.