I'm in the same position you are in... except was hoping to get word out and invites out at an event on the 1st. Just going to have to bite the bullet and let it slip. The tech is good but still has bugs. Not every hole has been plugged. Forgetting that code hasn't been optimized and speed is suffering, I just don't feel comfortable releasing a private beta yet. Next BIG launch target is in January and I'll open up an extremely limited private alpha/guinea pig site in the meantime.

I'm of the opinion that it doesn't mater how many (or how few) features you have, or even if what you have works, but what is paramount is that the UX is perfect. Not a single thing can be wrong with what you release. Anything that is will just scare away potential customers and give yoyu a rep for building crap.