Hope it's OK to post here :)
Just wanted to let you all know that I've released a little python-based tool for Inkscape that slices up files for use as web graphics. It doesn't yet generate (useful) HTML for you, but it's already quite flexible.
It has two different engines, so it can slice simple stuff based on ruler guidelines you quickly drag across an image, or if you need something more complex, you can create a special "slices" layer, with rectangles showing where each slice should be. Be sure to hide the slices layer before actually slicing, since the rectangles will be rendered in your slices otherwise*.
There is some future potential too: it could conceivably do much of what integrated slicers do (set file format for each slice etc.), thanks to the low-level XML access that Inkscape allows.
Available at: http://www.digitalunleashed.com/giving.php
Hopefully some of you will find this useful. Personally, I hate working with bitmap programs for web design :)
* It'd be great if there was some way to disable particular layers when calling inkscape from the shell for rendering.