For x2svg I implemented a simple GUI to drive the conversion for people that don't like the command line (see below for a screenshot).
This GUI also has a SVG viewer based on the batik / squiggle code built in.
But unfortunately, scaling / translating, the handling of the scroll bars and also the reaction on window resize don't really work well (or at all).
If you have a few spare cycles and some understanding on this part of AWT (and perhaps even the batik code additions on top of this), please help me fixing that part of the GUI.
Source code is visible on the sourceforge page and the class in question is SVGDisplayFrame.java.