I'm not sure why, but you can now launch Inkscape in a mode with a simple interactive shell. Someone submitted a patch a few weeks back that presented a "server" mode so they could run multiple Inkscape commands without actually relaunching the application.
I wasn't sure myself of where this would be most useful, but a few of our guys said it could help in some cases. I finally had time to clean up the bits of the implementation (though there still might be some lingering Windows issues) and get it submitted. There's a warning that pops up when exiting, but otherwise it seems ready to start using. We probably need to give a little thought to tweaks like the character or string for the prompt, etc. A bit more refinement is probably good.
It takes the same command format as the command-line interface that has been in Inkscape for some time. We might need to add a bit more, but finding out how people use it and what they run up against will probably shake all that out.