I'm using latest official Xvesa release and I think that /etc/slitaz-release was "stable". Searching for inkscape with tazpkg search inkscape give 0.47pre2. Switching to "cooking" release it print to me that there is no inkscape package. On online package search there is info about inkscape 0.47 in cooking mirror but there isn't link to package.
I remember recently looking at http://bb.slitaz.org and noting that inkscape was to be rebuilt in package form, but it failed for some reason. The cooking package for it was already deleted to make room for it. This is probably why it's missing in cooking for now.
Give it a couple of days, they're probably fixing this as we speak.