The comments in this post really demonstrate the widespread pain points that everyone has when dealing with CSS sprites, and the existence of 30+ solutions indicates that nobody has really figured out how to fix it yet.
The lack of attention to SVG stacks (http://simurai.com/post/20251013889/svg-stacks) is very curious to me - being a proponent of this method/movement seems analogous to being pro-PNG in the era of GIFs.