It's a read only mirror, the read/write mirror is on bkbits.net. But we'll maintain the mirror (or you can, bk has fast-export which creates a perfect mirror in git).
Would you describe the exporting process to git, pretty painless? If so, I'll look at adding bitkeeper support for my git analytics/search tool. I've uploaded some pictures that shows what the git repos that you have hosted on GitHub looks like at:
Since the export process adds "bk: <changeset>" to the commit comment, it'll be easy to tell that it was created via your fast-export tool, which means my tool can easily point you back to the bitkeeper web interface.
