Hey Alexandre!
I found a procedure for getting pdfs into svg reasonably well. It doesn't always work but when it does work, it seems pretty good.
First you need a program called pdftops (there is another called pdf2ps but it doesn't work; you need pdftops). I think it may be included with the xpdf package (http://www.foolabs.com/xpdf/). Its manpage says it is from "Glyph & Cog, LLC".
Now you can run this on your pdf files to produce ps files. This appears to work -ok-.
Second, you need scribus. This is from www.scribus.net.
Launch scribus and go to File->Import, then Import EPS/PS, and then select the PS file you created with pdf2ps.
Now check that the file loaded in scribus correctly. In my tests, I tried it on four random pdf files I had, each from a different source. Three of them loaded OK, one did not.
Third, go to File->Export, then Export as SVG. Type in the filename.svg and save it.
Finally, load the SVG up in Inkscape. Of the three that Scribus accepted, all three loaded into Inkscape.
However, one caveat... I found that all the text was converted into curves, so the PDF I took that was a letter came through uneditable. I also did a brochure that came through really poorly; the text wasn't even anti-aliased.
But... it did work.
Give this process a try and let me know what you think.
Bryce