Well, currently in Inkscape we can detect for these being installed, and remove options based on whether they are installed or not. So, I don't think it would be a big deal to use them.
There is also one problem in SVG because it doesn't put fill:none in style inkscape just fills everything in black:P..
Is this an SVG compliance thing, or can we fix this in Inkscape?
I think it's inkscape problem because if you add fill:none to there when it doesn't need filling everything looks fine.. I exam this one little bit more to I can say for sure.. this should be fixable in Inkscape.. I can provide example file if needed.
Now, I'm not sure I understood your e-mail, if we used pstoedit and plotutils, could that do all of the Illustrator importing? Or just certain versions of Illustrator?
If we have pstoedit compiled with plotutils one should could import these: Adobe Illustrator 10 [PDF 1.4] Photoshop CS files [PDF 1.4] PDF 1.2/1.3/1.4 Postscript
And possibly these: EPS should work(TM) (I haven't got time to try this)
You can't import these Adobe Illustrator 7 one needs ill2svg.pl. AI7 hava totaly diffrent format that is explained in one really big PDF that I found lately from Adobe's web site..
I just couldn't make myself clear sorry, Tuukka