Concerns about backwards compatibility of media fragments

Section 2.2.1 of http://www.w3.org/TR/2011/WD-media-frags-20110317/ says:

   An analysis of all media type registrations showed that there is
   not a single media type registration in the audio/*, image/*, video/*
   branches that is currently defining fragments or fragment semantics.

I'm not sure how this analysis was conducted, but image/svg+xml is 
defined to be SVG and SVG does in fact define fragment semantics.

This means that applying media fragments to SVG images, at the very 
least, would cause behavior changes in current UAs.

For an example, see the simple SVG testcase in 
http://lists.w3.org/Archives/Public/www-style/2011May/0114.html

I'm not quite sure what to do about this problem, honestly.

-Boris