Rewritten from scratch (#23, #30)
Dropped libxmljs dependency for improving Windows support (e.g. grunt-svg-sprite #14)
Added support for view, symbol and stack modes (#27, #35, grunt-svg-sprite #24)
Strip off all file access methods, making the module a good basis for 3rd party tools (like Grunt & Gulp plugins) (#21, #25)
Improved command line version (#34)
Switched to relative positioning in CSS sprites (grunt-svg-sprite #23)
Made the configuration of Mustache templates and destinations more intuitive
Enabled customization of shape IDs
Enabled custom SVG transformations
Enhanced padding options (#24)
Added cache busting for css and view mode (enabled by default; #29)
Added support for meta data injection

For older release notes please see here.

The original svg-sprite was my first-ever Node.js module and featured CSS sprites only. The 1.0 release is rewritten from scratch and introduces a bunch of new features like less dependencies (for improved Mac OS and Windows compatibility), support for inline sprite formats and the removal of file-system access so that other libraries can build on top of it more easily. Derived libraries include:

grunt-svg-sprite (a Grunt wrapper around svg-sprite)
gulp-svg-sprite (a Gulp wrapper around svg-sprite)
svg-sprite-data by Shane Osbourne (based on the original svg-sprite)

iconizr, another project of mine, is based on svg-sprite and adds PNG fallbacks for the sprites so you can use them as universal icon systems for websites (Node.js module, Grunt plugin, PHP version and online service).