BitBucket offers a hosted Mercurial hosting, combined with commit graphs, issue management, wiki, ... I played with it and it is certainly a great GitHub contender.
However when you are using the whole Atlassian stack, you have the following tools:
- Jira, an awesome issue management tool
- Confluence, a fantastic wiki
- FishEye with Crucible integration to manage and view source code
The thing you need to add yourself: a public Mercurial repository.
So right now, I'm asking what the main target audience/selling point for BitBucket is. Is it placed in the market as an easy introduction to the world of Atlassian? Are there some companies who are using BitBucket to host their code and if so, do you use the other features?