Last month I've been using Bitbucket for hosting my company's Mercurial repository.
I am admire of SaaS approach, but Bitbucket has succeeded proving me the opposite.
My repository is unavailable right now. And this happens much more offen than I expected from service dedicated for code hosting. pull/push operations take long time (up to 5-10 seconds). I have no idea how to make Mercurial so slow.
Maybe I'll give Assembla a try. But more probable, I'll rent a small VDS at Gandi and deploy my own Mercurial installation there.