There was a curious issue with rpm (my usual mis-build karma, I think), so I got rpm5 in place instead.
smart's working as well, but there's some testing in progress more to do with me understanding smart better.
I haven't touched yum yet, though, since smart's more exciting at the moment :)
So just in case Nexenta's Debian-alignment doesn't work out, we have a plan B at least (though I'm myself partial to rpm, to Centos's stability, and to Fedora's clean new packages).
What fun !