I installed Apache Batik for the first time last night. Batik is a Java library for SVG, particularly rasterising drawings. It did exactly what I needed (converting SVG graphs to PNG) without much fuss, either with installation or integration (I used the commandline rasteriser). I'd just not had a situation where I'd needed something other than Inkscape's commandline before.
I did have to install some nicer ttf fonts as there weren't any installed apart from Lucida in the JRE, but simply using aptitude to install an xfonts package worked.
It was a little slower than I had hoped, unfortunately, even for these very simple graphs, which means that working with this in web apps won't be quite as straightforward. It was much faster doing batches than individual graphs.
Anyway, server-side rasterisation is one obstacle to SVG adoption which happily proves relatively simple to overcome.