As I've reported in the UI Tools support page, I've started migrating the open source code I still have on bitbucket (Mercurial-based repos) to Github.
I didn't think that it might be worth a specific topic until @LogMAN mentioned it. Personally, I'm moving my code to Github in the process. I know there are some reports of Hg-to-Git transitions not going so well when using sub-repositories, so please share your migration experience if you've had to jump into some hoops to get it done!
For all of you who still use Mercurial and host your open source and/or enterprise repos on Bitbucket, this blog post is worth reading: