Yep, Smiler. I thought about that very issue hard before naming my blog SoloPoly.net. The trouble is, all the terms our language has to describe people who are unpartnered have vague-to-outright negative connotations or are just awkward. So I decided, at least for my own purposes, to reclaim "solo" and embrace it as a positive ace to start from. Not perfect, but better than most alternatives.
Also it applies more readily to folks who are in relationships -- just not primary-style (or primary-track) ones.