Hakon Lie proposed a notation for shadow text decoration as
text-decoration: shadow(red, 0.1em, 0.2em, 70%, 30%);
/* color, x-offset, y-offset, transparency, bluriness */
With support for multiple shadows, this proposal addresses all but
the most bizarre uses of duplicated text.
A consistent measurement for shadow is needed. Gaussian blur is the
usual method for blurring shadows, and this is specified as the
diameter of the area over which the effect propagates, not a
Scott Preece suggested an SRC=url form for bitmap shadows. This
limits an effect that would be more useful elsewhere. Background can
be either a color or a url. Why not color? As in:
Color as a url would allow texture bitmaps in both text and shadow.
Drop shadow is not just a text decoration. How about shadow as a
property for block elements, also?