I have the fortune of working with a printing house that actually uses Inkscape (and Scribus and The GIMP) in they day-to-day. This means that they know the intrincacies of the program and I can send them pure SVGs with the reassurance they will know what they are doing.
One of the problems I find, though, is that whenever I prepare a complex design (a poster, or even the layout of a page for simple books) where several font faces and external images are involved it is a real pain to gather all the resources (font files, image files) that I need to send them.
Sure, Inkscape can embed images (but this generates huge SVG files and becomes aggravating when an image is used repeatedly in several files). It can also generate PDFs which I can send to them (but sometimes they need to do preprinting and there is no good PDF editor for GNU/Linux, and PDF doesn't support all the features SVG and Inkscape do).
Hence I think that an option that parses the SVG file and generates a tarball with the SVG, its associated images and the relevant font faces would be very nice to have.