I really enjoyed that site. I've only posted on it once, but I enjoyed seeing other people's posts and appreciated reading about entrepreneurial dilemmas.
It didn't have enough ongoing activity, so it was closed down. It seems there were only a very small handful of regulars who were maintaining the site.
There are more details on the Startup Business site proposal on Area 51.
(Note that there is also a new proposal to try and get a new community of users around the topic.)