I'm with nyc. We're already here, we already know about it, and it already has a great domain. For those who want it, this site already has profiles and messaging and a calendar.
Also, fetlife itself has a number of poly groups, you can list poly as one of your kinks, and chat with other poly folk. I've met a few people on there who aren't otherwise kinky, but joined for the poly groups.
Poly folk already have challenges managing time between work, family, and relationships. This site takes up a fair bit of my time, which I enjoy. I personally don't have time to devote to yet another site.
An online community - not primarily a dating site - that allows individuals, couples, triads, and so on to meet and engage with other poly or poly-curious folks online.
Isn't that what we have here???