I'm sure this is on its way via WebGL shaders, but for the moment, another method besides using additional alpha-adjusted objects would be to use the SVGCanvas plugin, then use filters like in the following example.
SVGCanvas Text Drop Shadow
Here's the .capx: svgcanvas-text-drop-shadow.capx
It uses the drop shadow filter from the awesome and free, Inkscape and you can use any of the filters Inkscape provides by simply saving the SVG file, then copy-pasting the <filter> code.
Kudos to all those designer/developers who provide those incredible filters! And more better kudos to Pode for the SVGCanvas!