This is a feature request.
Since SVG is pretty much a text file, then it would be really nice to have the
ability to edit it directly through Wiki(p|M)edia interface. Sure, you might say
that editing SVG by hand is not easy but I belive it's much easier then editing
most Templates ;).
Allowing diff checks for differences would also be pretty logical to me.
I don't know how much changes does the code needs for this request, but please
think about it. This would really make images more wiki :).