A new plugin released by Adobe makes it possible to export your Adobe Illustrator images to XHTML/HTML5 and JavaScript. The plugin, Ai->Canvas, is free for all Adobe users, easy to install, and works for CS3, CS4 and CS5 on both Macs and PCs.
To learn more about the plugin, watch the interview with Mike Swanson (Source 2)
For SVG support it is recommended to download and use the Adobe Illustrator CS5 HTML5 Pack which is available on Adobe.com.
Source 1:
http://blogs.msdn.com/b/mswanson/archive/2010/10/12/adobe-illustrator-to-html5-canvas-plug-in-released.aspx
Source 2:
http://channel9.msdn.com/Shows/Going+Deep/Mike-Swanson-Adobe-Illustrator-to-HTML5-Canvas-Under-the-Hood#time=0h0m0s