yop,
A Sif to svg exist …
The page come from June 2009, and "All sif elements aren’t supported, so it may have a lot of glitchs. "… I have never use that feature. But seems to have animation capacity . Some svg from the sif2svg exemples in devll page kill my inkscape (macwolfen.svg).
But also exist, and it’s a transversale answer, a Sif html5 player github, few month old.
Actually support Region,Outline (without point width),Circle,Import (image),PasteCanvas,Scale,Translate, Rotate,Zoom,Stretch,Linear Gradient (without the params zigzag and loop),Radial Gradient (without the params zigzag and loop), layers.
Inkscape (himself), don’t really support animated svg right now “as developments continues, we’re now approaching the milestones that mentioned animation” cite…for sure this could be not so bad if synfig could be the first(?) software to produce fully & complex animated svg. If i’ts just about scripting (like sif2svg) this could be not so much exesivly too hard (with some maybe inside).
But in any case so easy than the complex plan on terminology 
Svg file format come from “World Wide Web Consortium” / w3c , they try take care of standards around the big net…i’m not convicted that creating animated svg , they think in term of film quality animation … what synfig aim to produce … in other terms, .sif is more than animated .svg
see(:ya!